Duplicated symbol error after compiling against `libsecp256k1@v0.7.0`

[nymius]

Description:
While implementing the rust-secp256k1 bindings for silentpayments, #876 I hit a duplicated symbol error when running tests, after building the library against the tip of the libsecp256k1 branch including the silent payment module.

I traced the error back to the last commit in libsecp256k1 against which rust-secp256k1 bindings compiled and ran tests normally.

The latest working commit is: bitcoin-core/secp256k1@1b1fc09
The first commit on which the duplicated symbol error appears is: bitcoin-core/secp256k1@432ac57

This commit belongs to the libsecp256k1@v0.7.0 release.

The error is triggered by the change from a const <type> *<var> to a const <type> *const <var>.
I'm having a hard time understanding the origin of the issue.

Full `duplicated symbol` error

$ cargo test
   Compiling serde v1.0.217
   Compiling hex_lit v0.1.1
   Compiling rand_core v0.9.3
   Compiling half v1.8.3
   Compiling byteorder v1.5.0
   Compiling rand_xoshiro v0.7.0
   Compiling bincode v1.3.3
   Compiling serde_test v1.0.177
   Compiling serde_cbor v0.10.2
   Compiling secp256k1 v0.32.0-beta.2 (~/rust-secp256k1)
error: linking with `cc` failed: exit status: 1
  |
  = note:  "cc" "-m64" "/tmp/rustc2xYw0V/symbols.o" "<17 object files omitted>" "-Wl,--as-needed" "-Wl,-Bstatic" "~/rust-secp256k1/target/debug/deps/{libsecp256k1-a0b13cfe2052608d,libsecp256k1_sys-b1b59c933f23d7ba}.rlib" "<sysroot>/lib/rustlib/x86_64-unknown-linux-gnu/lib/{libstd-*,libpanic_unwind-*,libobject-*,libmemchr-*,libaddr2line-*,libgimli-*,libcfg_if-*,librustc_demangle-*,libstd_detect-*,libhashbrown-*,librustc_std_workspace_alloc-*,libminiz_oxide-*,libadler2-*,libunwind-*,liblibc-*,librustc_std_workspace_core-*,liballoc-*,libcore-*,libcompiler_builtins-*}.rlib" "-Wl,-Bdynamic" "-lgcc_s" "-lutil" "-lrt" "-lpthread" "-lm" "-ldl" "-lc" "-L" "/tmp/rustc2xYw0V/raw-dylibs" "-B<sysroot>/lib/rustlib/x86_64-unknown-linux-gnu/bin/gcc-ld" "-fuse-ld=lld" "-Wl,--eh-frame-hdr" "-Wl,-z,noexecstack" "-L" "~/rust-secp256k1/target/debug/build/secp256k1-sys-26ff80809ab77d67/out" "-L" "<sysroot>/lib/rustlib/x86_64-unknown-linux-gnu/lib" "-o" "~/rust-secp256k1/target/debug/examples/sign_verify-44611d3e60e6c624" "-Wl,--gc-sections" "-pie" "-Wl,-z,relro,-z,now" "-nodefaultlibs"
  = note: some arguments are omitted. use `--verbose` to show all linker arguments
  = note: rust-lld: error: duplicate symbol: rustsecp256k1_v0_12_context_static
          >>> defined at secp256k1.h:233 (depend/secp256k1/include/secp256k1.h:233)
          >>>            4d6b2bbe68124288-lax_der_parsing.o:(rustsecp256k1_v0_12_context_static) in archive ~/rust-secp256k1/target/debug/deps/libsecp256k1_sys-b1b59c933f23d7ba.rlib
          >>> defined at secp256k1.h:233 (depend/secp256k1/src/../include/secp256k1.h:233)
          >>>            fce6141bfa9bf74c-secp256k1.o:(.data.rel.ro.local.rustsecp256k1_v0_12_context_static+0x0) in archive ~/rust-secp256k1/target/debug/deps/libsecp256k1_sys-b1b59c933f23d7ba.rlib

          rust-lld: error: duplicate symbol: rustsecp256k1_v0_12_context_no_precomp
          >>> defined at secp256k1.h:236 (depend/secp256k1/include/secp256k1.h:236)
          >>>            4d6b2bbe68124288-lax_der_parsing.o:(rustsecp256k1_v0_12_context_no_precomp) in archive ~/rust-secp256k1/target/debug/deps/libsecp256k1_sys-b1b59c933f23d7ba.rlib
          >>> defined at secp256k1.h:236 (depend/secp256k1/src/../include/secp256k1.h:236)
          >>>            fce6141bfa9bf74c-secp256k1.o:(.data.rel.ro.local.rustsecp256k1_v0_12_context_no_precomp+0x0) in archive ~/rust-secp256k1/target/debug/deps/libsecp256k1_sys-b1b59c933f23d7ba.rlib

          rust-lld: error: duplicate symbol: rustsecp256k1_v0_12_nonce_function_rfc6979
          >>> defined at secp256k1.h:638 (depend/secp256k1/include/secp256k1.h:638)
          >>>            4d6b2bbe68124288-lax_der_parsing.o:(rustsecp256k1_v0_12_nonce_function_rfc6979) in archive ~/rust-secp256k1/target/debug/deps/libsecp256k1_sys-b1b59c933f23d7ba.rlib
          >>> defined at secp256k1.h:638 (depend/secp256k1/src/../include/secp256k1.h:638)
          >>>            fce6141bfa9bf74c-secp256k1.o:(.data.rel.ro.local.rustsecp256k1_v0_12_nonce_function_rfc6979+0x0) in archive ~/rust-secp256k1/target/debug/deps/libsecp256k1_sys-b1b59c933f23d7ba.rlib

          rust-lld: error: duplicate symbol: rustsecp256k1_v0_12_nonce_function_default
          >>> defined at secp256k1.h:641 (depend/secp256k1/include/secp256k1.h:641)
          >>>            4d6b2bbe68124288-lax_der_parsing.o:(rustsecp256k1_v0_12_nonce_function_default) in archive ~/rust-secp256k1/target/debug/deps/libsecp256k1_sys-b1b59c933f23d7ba.rlib
          >>> defined at secp256k1.h:641 (depend/secp256k1/src/../include/secp256k1.h:641)
          >>>            fce6141bfa9bf74c-secp256k1.o:(.data.rel.ro.local.rustsecp256k1_v0_12_nonce_function_default+0x0) in archive ~/rust-secp256k1/target/debug/deps/libsecp256k1_sys-b1b59c933f23d7ba.rlib

          rust-lld: error: duplicate symbol: rustsecp256k1_v0_12_context_static
          >>> defined at secp256k1.h:233 (depend/secp256k1/include/secp256k1.h:233)
          >>>            4d6b2bbe68124288-lax_der_parsing.o:(rustsecp256k1_v0_12_context_static) in archive ~/rust-secp256k1/target/debug/deps/libsecp256k1_sys-b1b59c933f23d7ba.rlib
          >>> defined at secp256k1.h:233 (depend/secp256k1/src/../include/secp256k1.h:233)
          >>>            fce6141bfa9bf74c-precomputed_ecmult_gen.o:(.rodata.rustsecp256k1_v0_12_context_static+0x0) in archive ~/rust-secp256k1/target/debug/deps/libsecp256k1_sys-b1b59c933f23d7ba.rlib

          rust-lld: error: duplicate symbol: rustsecp256k1_v0_12_context_no_precomp
          >>> defined at secp256k1.h:236 (depend/secp256k1/include/secp256k1.h:236)
          >>>            4d6b2bbe68124288-lax_der_parsing.o:(rustsecp256k1_v0_12_context_no_precomp) in archive ~/rust-secp256k1/target/debug/deps/libsecp256k1_sys-b1b59c933f23d7ba.rlib
          >>> defined at secp256k1.h:236 (depend/secp256k1/src/../include/secp256k1.h:236)
          >>>            fce6141bfa9bf74c-precomputed_ecmult_gen.o:(.rodata.rustsecp256k1_v0_12_context_no_precomp+0x0) in archive ~/rust-secp256k1/target/debug/deps/libsecp256k1_sys-b1b59c933f23d7ba.rlib

          rust-lld: error: duplicate symbol: rustsecp256k1_v0_12_nonce_function_rfc6979
          >>> defined at secp256k1.h:638 (depend/secp256k1/include/secp256k1.h:638)
          >>>            4d6b2bbe68124288-lax_der_parsing.o:(rustsecp256k1_v0_12_nonce_function_rfc6979) in archive ~/rust-secp256k1/target/debug/deps/libsecp256k1_sys-b1b59c933f23d7ba.rlib
          >>> defined at secp256k1.h:638 (depend/secp256k1/src/../include/secp256k1.h:638)
          >>>            fce6141bfa9bf74c-precomputed_ecmult_gen.o:(.rodata.rustsecp256k1_v0_12_nonce_function_rfc6979+0x0) in archive ~/rust-secp256k1/target/debug/deps/libsecp256k1_sys-b1b59c933f23d7ba.rlib

          rust-lld: error: duplicate symbol: rustsecp256k1_v0_12_nonce_function_default
          >>> defined at secp256k1.h:641 (depend/secp256k1/include/secp256k1.h:641)
          >>>            4d6b2bbe68124288-lax_der_parsing.o:(rustsecp256k1_v0_12_nonce_function_default) in archive ~/rust-secp256k1/target/debug/deps/libsecp256k1_sys-b1b59c933f23d7ba.rlib
          >>> defined at secp256k1.h:641 (depend/secp256k1/src/../include/secp256k1.h:641)
          >>>            fce6141bfa9bf74c-precomputed_ecmult_gen.o:(.rodata.rustsecp256k1_v0_12_nonce_function_default+0x0) in archive ~/rust-secp256k1/target/debug/deps/libsecp256k1_sys-b1b59c933f23d7ba.rlib

          rust-lld: error: duplicate symbol: rustsecp256k1_v0_12_context_static
          >>> defined at secp256k1.h:233 (depend/secp256k1/include/secp256k1.h:233)
          >>>            4d6b2bbe68124288-lax_der_parsing.o:(rustsecp256k1_v0_12_context_static) in archive ~/rust-secp256k1/target/debug/deps/libsecp256k1_sys-b1b59c933f23d7ba.rlib
          >>> defined at secp256k1.h:233 (depend/secp256k1/src/../include/secp256k1.h:233)
          >>>            fce6141bfa9bf74c-precomputed_ecmult.o:(.rodata.rustsecp256k1_v0_12_context_static+0x0) in archive ~/rust-secp256k1/target/debug/deps/libsecp256k1_sys-b1b59c933f23d7ba.rlib

          rust-lld: error: duplicate symbol: rustsecp256k1_v0_12_context_no_precomp
          >>> defined at secp256k1.h:236 (depend/secp256k1/include/secp256k1.h:236)
          >>>            4d6b2bbe68124288-lax_der_parsing.o:(rustsecp256k1_v0_12_context_no_precomp) in archive ~/rust-secp256k1/target/debug/deps/libsecp256k1_sys-b1b59c933f23d7ba.rlib
          >>> defined at secp256k1.h:236 (depend/secp256k1/src/../include/secp256k1.h:236)
          >>>            fce6141bfa9bf74c-precomputed_ecmult.o:(.rodata.rustsecp256k1_v0_12_context_no_precomp+0x0) in archive ~/rust-secp256k1/target/debug/deps/libsecp256k1_sys-b1b59c933f23d7ba.rlib

          rust-lld: error: duplicate symbol: rustsecp256k1_v0_12_nonce_function_rfc6979
          >>> defined at secp256k1.h:638 (depend/secp256k1/include/secp256k1.h:638)
          >>>            4d6b2bbe68124288-lax_der_parsing.o:(rustsecp256k1_v0_12_nonce_function_rfc6979) in archive ~/rust-secp256k1/target/debug/deps/libsecp256k1_sys-b1b59c933f23d7ba.rlib
          >>> defined at secp256k1.h:638 (depend/secp256k1/src/../include/secp256k1.h:638)
          >>>            fce6141bfa9bf74c-precomputed_ecmult.o:(.rodata.rustsecp256k1_v0_12_nonce_function_rfc6979+0x0) in archive ~/rust-secp256k1/target/debug/deps/libsecp256k1_sys-b1b59c933f23d7ba.rlib

          rust-lld: error: duplicate symbol: rustsecp256k1_v0_12_nonce_function_default
          >>> defined at secp256k1.h:641 (depend/secp256k1/include/secp256k1.h:641)
          >>>            4d6b2bbe68124288-lax_der_parsing.o:(rustsecp256k1_v0_12_nonce_function_default) in archive ~/rust-secp256k1/target/debug/deps/libsecp256k1_sys-b1b59c933f23d7ba.rlib
          >>> defined at secp256k1.h:641 (depend/secp256k1/src/../include/secp256k1.h:641)
          >>>            fce6141bfa9bf74c-precomputed_ecmult.o:(.rodata.rustsecp256k1_v0_12_nonce_function_default+0x0) in archive ~/rust-secp256k1/target/debug/deps/libsecp256k1_sys-b1b59c933f23d7ba.rlib
          collect2: error: ld returned 1 exit status


error: could not compile `secp256k1` (example "sign_verify") due to 1 previous error
warning: build failed, waiting for other jobs to finish...
error: linking with `cc` failed: exit status: 1
  |
  = note:  "cc" "-m64" "/tmp/rustcMguYmr/symbols.o" "<6 object files omitted>" "-Wl,--as-needed" "-Wl,-Bstatic" "<sysroot>/lib/rustlib/x86_64-unknown-linux-gnu/lib/{libtest-*,libgetopts-*,librustc_std_workspace_std-*}.rlib" "~/rust-secp256k1/target/debug/deps/{libsecp256k1-a0b13cfe2052608d,libsecp256k1_sys-b1b59c933f23d7ba}.rlib" "<sysroot>/lib/rustlib/x86_64-unknown-linux-gnu/lib/{libstd-*,libpanic_unwind-*,libobject-*,libmemchr-*,libaddr2line-*,libgimli-*,libcfg_if-*,librustc_demangle-*,libstd_detect-*,libhashbrown-*,librustc_std_workspace_alloc-*,libminiz_oxide-*,libadler2-*,libunwind-*,liblibc-*,librustc_std_workspace_core-*,liballoc-*,libcore-*,libcompiler_builtins-*}.rlib" "-Wl,-Bdynamic" "-lgcc_s" "-lutil" "-lrt" "-lpthread" "-lm" "-ldl" "-lc" "-L" "/tmp/rustcMguYmr/raw-dylibs" "-B<sysroot>/lib/rustlib/x86_64-unknown-linux-gnu/bin/gcc-ld" "-fuse-ld=lld" "-Wl,--eh-frame-hdr" "-Wl,-z,noexecstack" "-L" "~/rust-secp256k1/target/debug/build/secp256k1-sys-26ff80809ab77d67/out" "-L" "<sysroot>/lib/rustlib/x86_64-unknown-linux-gnu/lib" "-o" "~/rust-secp256k1/target/debug/deps/api-5fb020599b5dc4b5" "-Wl,--gc-sections" "-pie" "-Wl,-z,relro,-z,now" "-nodefaultlibs"
  = note: some arguments are omitted. use `--verbose` to show all linker arguments
  = note: rust-lld: error: duplicate symbol: rustsecp256k1_v0_12_context_static
          >>> defined at secp256k1.h:233 (depend/secp256k1/include/secp256k1.h:233)
          >>>            4d6b2bbe68124288-lax_der_parsing.o:(rustsecp256k1_v0_12_context_static) in archive ~/rust-secp256k1/target/debug/deps/libsecp256k1_sys-b1b59c933f23d7ba.rlib
          >>> defined at secp256k1.h:233 (depend/secp256k1/src/../include/secp256k1.h:233)
          >>>            fce6141bfa9bf74c-secp256k1.o:(.data.rel.ro.local.rustsecp256k1_v0_12_context_static+0x0) in archive ~/rust-secp256k1/target/debug/deps/libsecp256k1_sys-b1b59c933f23d7ba.rlib

          rust-lld: error: duplicate symbol: rustsecp256k1_v0_12_context_no_precomp
          >>> defined at secp256k1.h:236 (depend/secp256k1/include/secp256k1.h:236)
          >>>            4d6b2bbe68124288-lax_der_parsing.o:(rustsecp256k1_v0_12_context_no_precomp) in archive ~/rust-secp256k1/target/debug/deps/libsecp256k1_sys-b1b59c933f23d7ba.rlib
          >>> defined at secp256k1.h:236 (depend/secp256k1/src/../include/secp256k1.h:236)
          >>>            fce6141bfa9bf74c-secp256k1.o:(.data.rel.ro.local.rustsecp256k1_v0_12_context_no_precomp+0x0) in archive ~/rust-secp256k1/target/debug/deps/libsecp256k1_sys-b1b59c933f23d7ba.rlib

          rust-lld: error: duplicate symbol: rustsecp256k1_v0_12_nonce_function_rfc6979
          >>> defined at secp256k1.h:638 (depend/secp256k1/include/secp256k1.h:638)
          >>>            4d6b2bbe68124288-lax_der_parsing.o:(rustsecp256k1_v0_12_nonce_function_rfc6979) in archive ~/rust-secp256k1/target/debug/deps/libsecp256k1_sys-b1b59c933f23d7ba.rlib
          >>> defined at secp256k1.h:638 (depend/secp256k1/src/../include/secp256k1.h:638)
          >>>            fce6141bfa9bf74c-secp256k1.o:(.data.rel.ro.local.rustsecp256k1_v0_12_nonce_function_rfc6979+0x0) in archive ~/rust-secp256k1/target/debug/deps/libsecp256k1_sys-b1b59c933f23d7ba.rlib

          rust-lld: error: duplicate symbol: rustsecp256k1_v0_12_nonce_function_default
          >>> defined at secp256k1.h:641 (depend/secp256k1/include/secp256k1.h:641)
          >>>            4d6b2bbe68124288-lax_der_parsing.o:(rustsecp256k1_v0_12_nonce_function_default) in archive ~/rust-secp256k1/target/debug/deps/libsecp256k1_sys-b1b59c933f23d7ba.rlib
          >>> defined at secp256k1.h:641 (depend/secp256k1/src/../include/secp256k1.h:641)
          >>>            fce6141bfa9bf74c-secp256k1.o:(.data.rel.ro.local.rustsecp256k1_v0_12_nonce_function_default+0x0) in archive ~/rust-secp256k1/target/debug/deps/libsecp256k1_sys-b1b59c933f23d7ba.rlib

          rust-lld: error: duplicate symbol: rustsecp256k1_v0_12_context_static
          >>> defined at secp256k1.h:233 (depend/secp256k1/include/secp256k1.h:233)
          >>>            4d6b2bbe68124288-lax_der_parsing.o:(rustsecp256k1_v0_12_context_static) in archive ~/rust-secp256k1/target/debug/deps/libsecp256k1_sys-b1b59c933f23d7ba.rlib
          >>> defined at secp256k1.h:233 (depend/secp256k1/src/../include/secp256k1.h:233)
          >>>            fce6141bfa9bf74c-precomputed_ecmult.o:(.rodata.rustsecp256k1_v0_12_context_static+0x0) in archive ~/rust-secp256k1/target/debug/deps/libsecp256k1_sys-b1b59c933f23d7ba.rlib

          rust-lld: error: duplicate symbol: rustsecp256k1_v0_12_context_no_precomp
          >>> defined at secp256k1.h:236 (depend/secp256k1/include/secp256k1.h:236)
          >>>            4d6b2bbe68124288-lax_der_parsing.o:(rustsecp256k1_v0_12_context_no_precomp) in archive ~/rust-secp256k1/target/debug/deps/libsecp256k1_sys-b1b59c933f23d7ba.rlib
          >>> defined at secp256k1.h:236 (depend/secp256k1/src/../include/secp256k1.h:236)
          >>>            fce6141bfa9bf74c-precomputed_ecmult.o:(.rodata.rustsecp256k1_v0_12_context_no_precomp+0x0) in archive ~/rust-secp256k1/target/debug/deps/libsecp256k1_sys-b1b59c933f23d7ba.rlib

          rust-lld: error: duplicate symbol: rustsecp256k1_v0_12_nonce_function_rfc6979
          >>> defined at secp256k1.h:638 (depend/secp256k1/include/secp256k1.h:638)
          >>>            4d6b2bbe68124288-lax_der_parsing.o:(rustsecp256k1_v0_12_nonce_function_rfc6979) in archive ~/rust-secp256k1/target/debug/deps/libsecp256k1_sys-b1b59c933f23d7ba.rlib
          >>> defined at secp256k1.h:638 (depend/secp256k1/src/../include/secp256k1.h:638)
          >>>            fce6141bfa9bf74c-precomputed_ecmult.o:(.rodata.rustsecp256k1_v0_12_nonce_function_rfc6979+0x0) in archive ~/rust-secp256k1/target/debug/deps/libsecp256k1_sys-b1b59c933f23d7ba.rlib

          rust-lld: error: duplicate symbol: rustsecp256k1_v0_12_nonce_function_default
          >>> defined at secp256k1.h:641 (depend/secp256k1/include/secp256k1.h:641)
          >>>            4d6b2bbe68124288-lax_der_parsing.o:(rustsecp256k1_v0_12_nonce_function_default) in archive ~/rust-secp256k1/target/debug/deps/libsecp256k1_sys-b1b59c933f23d7ba.rlib
          >>> defined at secp256k1.h:641 (depend/secp256k1/src/../include/secp256k1.h:641)
          >>>            fce6141bfa9bf74c-precomputed_ecmult.o:(.rodata.rustsecp256k1_v0_12_nonce_function_default+0x0) in archive ~/rust-secp256k1/target/debug/deps/libsecp256k1_sys-b1b59c933f23d7ba.rlib

          rust-lld: error: duplicate symbol: rustsecp256k1_v0_12_context_static
          >>> defined at secp256k1.h:233 (depend/secp256k1/include/secp256k1.h:233)
          >>>            4d6b2bbe68124288-lax_der_parsing.o:(rustsecp256k1_v0_12_context_static) in archive ~/rust-secp256k1/target/debug/deps/libsecp256k1_sys-b1b59c933f23d7ba.rlib
          >>> defined at secp256k1.h:233 (depend/secp256k1/src/../include/secp256k1.h:233)
          >>>            fce6141bfa9bf74c-precomputed_ecmult_gen.o:(.rodata.rustsecp256k1_v0_12_context_static+0x0) in archive ~/rust-secp256k1/target/debug/deps/libsecp256k1_sys-b1b59c933f23d7ba.rlib

          rust-lld: error: duplicate symbol: rustsecp256k1_v0_12_context_no_precomp
          >>> defined at secp256k1.h:236 (depend/secp256k1/include/secp256k1.h:236)
          >>>            4d6b2bbe68124288-lax_der_parsing.o:(rustsecp256k1_v0_12_context_no_precomp) in archive ~/rust-secp256k1/target/debug/deps/libsecp256k1_sys-b1b59c933f23d7ba.rlib
          >>> defined at secp256k1.h:236 (depend/secp256k1/src/../include/secp256k1.h:236)
          >>>            fce6141bfa9bf74c-precomputed_ecmult_gen.o:(.rodata.rustsecp256k1_v0_12_context_no_precomp+0x0) in archive ~/rust-secp256k1/target/debug/deps/libsecp256k1_sys-b1b59c933f23d7ba.rlib

          rust-lld: error: duplicate symbol: rustsecp256k1_v0_12_nonce_function_rfc6979
          >>> defined at secp256k1.h:638 (depend/secp256k1/include/secp256k1.h:638)
          >>>            4d6b2bbe68124288-lax_der_parsing.o:(rustsecp256k1_v0_12_nonce_function_rfc6979) in archive ~/rust-secp256k1/target/debug/deps/libsecp256k1_sys-b1b59c933f23d7ba.rlib
          >>> defined at secp256k1.h:638 (depend/secp256k1/src/../include/secp256k1.h:638)
          >>>            fce6141bfa9bf74c-precomputed_ecmult_gen.o:(.rodata.rustsecp256k1_v0_12_nonce_function_rfc6979+0x0) in archive ~/rust-secp256k1/target/debug/deps/libsecp256k1_sys-b1b59c933f23d7ba.rlib

          rust-lld: error: duplicate symbol: rustsecp256k1_v0_12_nonce_function_default
          >>> defined at secp256k1.h:641 (depend/secp256k1/include/secp256k1.h:641)
          >>>            4d6b2bbe68124288-lax_der_parsing.o:(rustsecp256k1_v0_12_nonce_function_default) in archive ~/rust-secp256k1/target/debug/deps/libsecp256k1_sys-b1b59c933f23d7ba.rlib
          >>> defined at secp256k1.h:641 (depend/secp256k1/src/../include/secp256k1.h:641)
          >>>            fce6141bfa9bf74c-precomputed_ecmult_gen.o:(.rodata.rustsecp256k1_v0_12_nonce_function_default+0x0) in archive ~/rust-secp256k1/target/debug/deps/libsecp256k1_sys-b1b59c933f23d7ba.rlib
          collect2: error: ld returned 1 exit status


error: could not compile `secp256k1` (test "api") due to 1 previous error
error: linking with `cc` failed: exit status: 1
  |
  = note:  "cc" "-m64" "/tmp/rustcxQ3jML/symbols.o" "<136 object files omitted>" "-Wl,--as-needed" "-Wl,-Bstatic" "<sysroot>/lib/rustlib/x86_64-unknown-linux-gnu/lib/{libtest-*,libgetopts-*,librustc_std_workspace_std-*}.rlib" "~/rust-secp256k1/target/debug/deps/{libserde_test-8e6afadce4872644,libserde-2e3dac7503457b0b,libhex_lit-26a49f471131e64f,libsecp256k1_sys-b1b59c933f23d7ba}.rlib" "<sysroot>/lib/rustlib/x86_64-unknown-linux-gnu/lib/{libstd-*,libpanic_unwind-*,libobject-*,libmemchr-*,libaddr2line-*,libgimli-*,libcfg_if-*,librustc_demangle-*,libstd_detect-*,libhashbrown-*,librustc_std_workspace_alloc-*,libminiz_oxide-*,libadler2-*,libunwind-*,liblibc-*,librustc_std_workspace_core-*,liballoc-*,libcore-*,libcompiler_builtins-*}.rlib" "-Wl,-Bdynamic" "-lgcc_s" "-lutil" "-lrt" "-lpthread" "-lm" "-ldl" "-lc" "-L" "/tmp/rustcxQ3jML/raw-dylibs" "-B<sysroot>/lib/rustlib/x86_64-unknown-linux-gnu/bin/gcc-ld" "-fuse-ld=lld" "-Wl,--eh-frame-hdr" "-Wl,-z,noexecstack" "-L" "~/rust-secp256k1/target/debug/build/secp256k1-sys-26ff80809ab77d67/out" "-L" "<sysroot>/lib/rustlib/x86_64-unknown-linux-gnu/lib" "-o" "~/rust-secp256k1/target/debug/deps/secp256k1-411d26ba1b5f353b" "-Wl,--gc-sections" "-pie" "-Wl,-z,relro,-z,now" "-nodefaultlibs"
  = note: some arguments are omitted. use `--verbose` to show all linker arguments
  = note: rust-lld: error: duplicate symbol: rustsecp256k1_v0_12_context_static
          >>> defined at secp256k1.h:233 (depend/secp256k1/include/secp256k1.h:233)
          >>>            4d6b2bbe68124288-lax_der_parsing.o:(rustsecp256k1_v0_12_context_static) in archive ~/rust-secp256k1/target/debug/deps/libsecp256k1_sys-b1b59c933f23d7ba.rlib
          >>> defined at secp256k1.h:233 (depend/secp256k1/src/../include/secp256k1.h:233)
          >>>            fce6141bfa9bf74c-precomputed_ecmult.o:(.rodata.rustsecp256k1_v0_12_context_static+0x0) in archive ~/rust-secp256k1/target/debug/deps/libsecp256k1_sys-b1b59c933f23d7ba.rlib

          rust-lld: error: duplicate symbol: rustsecp256k1_v0_12_context_no_precomp
          >>> defined at secp256k1.h:236 (depend/secp256k1/include/secp256k1.h:236)
          >>>            4d6b2bbe68124288-lax_der_parsing.o:(rustsecp256k1_v0_12_context_no_precomp) in archive ~/rust-secp256k1/target/debug/deps/libsecp256k1_sys-b1b59c933f23d7ba.rlib
          >>> defined at secp256k1.h:236 (depend/secp256k1/src/../include/secp256k1.h:236)
          >>>            fce6141bfa9bf74c-precomputed_ecmult.o:(.rodata.rustsecp256k1_v0_12_context_no_precomp+0x0) in archive ~/rust-secp256k1/target/debug/deps/libsecp256k1_sys-b1b59c933f23d7ba.rlib

          rust-lld: error: duplicate symbol: rustsecp256k1_v0_12_nonce_function_rfc6979
          >>> defined at secp256k1.h:638 (depend/secp256k1/include/secp256k1.h:638)
          >>>            4d6b2bbe68124288-lax_der_parsing.o:(rustsecp256k1_v0_12_nonce_function_rfc6979) in archive ~/rust-secp256k1/target/debug/deps/libsecp256k1_sys-b1b59c933f23d7ba.rlib
          >>> defined at secp256k1.h:638 (depend/secp256k1/src/../include/secp256k1.h:638)
          >>>            fce6141bfa9bf74c-precomputed_ecmult.o:(.rodata.rustsecp256k1_v0_12_nonce_function_rfc6979+0x0) in archive ~/rust-secp256k1/target/debug/deps/libsecp256k1_sys-b1b59c933f23d7ba.rlib

          rust-lld: error: duplicate symbol: rustsecp256k1_v0_12_nonce_function_default
          >>> defined at secp256k1.h:641 (depend/secp256k1/include/secp256k1.h:641)
          >>>            4d6b2bbe68124288-lax_der_parsing.o:(rustsecp256k1_v0_12_nonce_function_default) in archive ~/rust-secp256k1/target/debug/deps/libsecp256k1_sys-b1b59c933f23d7ba.rlib
          >>> defined at secp256k1.h:641 (depend/secp256k1/src/../include/secp256k1.h:641)
          >>>            fce6141bfa9bf74c-precomputed_ecmult.o:(.rodata.rustsecp256k1_v0_12_nonce_function_default+0x0) in archive ~/rust-secp256k1/target/debug/deps/libsecp256k1_sys-b1b59c933f23d7ba.rlib

          rust-lld: error: duplicate symbol: rustsecp256k1_v0_12_context_static
          >>> defined at secp256k1.h:233 (depend/secp256k1/include/secp256k1.h:233)
          >>>            4d6b2bbe68124288-lax_der_parsing.o:(rustsecp256k1_v0_12_context_static) in archive ~/rust-secp256k1/target/debug/deps/libsecp256k1_sys-b1b59c933f23d7ba.rlib
          >>> defined at secp256k1.h:233 (depend/secp256k1/src/../include/secp256k1.h:233)
          >>>            fce6141bfa9bf74c-precomputed_ecmult_gen.o:(.rodata.rustsecp256k1_v0_12_context_static+0x0) in archive ~/rust-secp256k1/target/debug/deps/libsecp256k1_sys-b1b59c933f23d7ba.rlib

          rust-lld: error: duplicate symbol: rustsecp256k1_v0_12_context_no_precomp
          >>> defined at secp256k1.h:236 (depend/secp256k1/include/secp256k1.h:236)
          >>>            4d6b2bbe68124288-lax_der_parsing.o:(rustsecp256k1_v0_12_context_no_precomp) in archive ~/rust-secp256k1/target/debug/deps/libsecp256k1_sys-b1b59c933f23d7ba.rlib
          >>> defined at secp256k1.h:236 (depend/secp256k1/src/../include/secp256k1.h:236)
          >>>            fce6141bfa9bf74c-precomputed_ecmult_gen.o:(.rodata.rustsecp256k1_v0_12_context_no_precomp+0x0) in archive ~/rust-secp256k1/target/debug/deps/libsecp256k1_sys-b1b59c933f23d7ba.rlib

          rust-lld: error: duplicate symbol: rustsecp256k1_v0_12_nonce_function_rfc6979
          >>> defined at secp256k1.h:638 (depend/secp256k1/include/secp256k1.h:638)
          >>>            4d6b2bbe68124288-lax_der_parsing.o:(rustsecp256k1_v0_12_nonce_function_rfc6979) in archive ~/rust-secp256k1/target/debug/deps/libsecp256k1_sys-b1b59c933f23d7ba.rlib
          >>> defined at secp256k1.h:638 (depend/secp256k1/src/../include/secp256k1.h:638)
          >>>            fce6141bfa9bf74c-precomputed_ecmult_gen.o:(.rodata.rustsecp256k1_v0_12_nonce_function_rfc6979+0x0) in archive ~/rust-secp256k1/target/debug/deps/libsecp256k1_sys-b1b59c933f23d7ba.rlib

          rust-lld: error: duplicate symbol: rustsecp256k1_v0_12_nonce_function_default
          >>> defined at secp256k1.h:641 (depend/secp256k1/include/secp256k1.h:641)
          >>>            4d6b2bbe68124288-lax_der_parsing.o:(rustsecp256k1_v0_12_nonce_function_default) in archive ~/rust-secp256k1/target/debug/deps/libsecp256k1_sys-b1b59c933f23d7ba.rlib
          >>> defined at secp256k1.h:641 (depend/secp256k1/src/../include/secp256k1.h:641)
          >>>            fce6141bfa9bf74c-precomputed_ecmult_gen.o:(.rodata.rustsecp256k1_v0_12_nonce_function_default+0x0) in archive ~/rust-secp256k1/target/debug/deps/libsecp256k1_sys-b1b59c933f23d7ba.rlib

          rust-lld: error: duplicate symbol: rustsecp256k1_v0_12_context_static
          >>> defined at secp256k1.h:233 (depend/secp256k1/include/secp256k1.h:233)
          >>>            4d6b2bbe68124288-lax_der_parsing.o:(rustsecp256k1_v0_12_context_static) in archive ~/rust-secp256k1/target/debug/deps/libsecp256k1_sys-b1b59c933f23d7ba.rlib
          >>> defined at secp256k1.h:233 (depend/secp256k1/src/../include/secp256k1.h:233)
          >>>            fce6141bfa9bf74c-secp256k1.o:(.data.rel.ro.local.rustsecp256k1_v0_12_context_static+0x0) in archive ~/rust-secp256k1/target/debug/deps/libsecp256k1_sys-b1b59c933f23d7ba.rlib

          rust-lld: error: duplicate symbol: rustsecp256k1_v0_12_context_no_precomp
          >>> defined at secp256k1.h:236 (depend/secp256k1/include/secp256k1.h:236)
          >>>            4d6b2bbe68124288-lax_der_parsing.o:(rustsecp256k1_v0_12_context_no_precomp) in archive ~/rust-secp256k1/target/debug/deps/libsecp256k1_sys-b1b59c933f23d7ba.rlib
          >>> defined at secp256k1.h:236 (depend/secp256k1/src/../include/secp256k1.h:236)
          >>>            fce6141bfa9bf74c-secp256k1.o:(.data.rel.ro.local.rustsecp256k1_v0_12_context_no_precomp+0x0) in archive ~/rust-secp256k1/target/debug/deps/libsecp256k1_sys-b1b59c933f23d7ba.rlib

          rust-lld: error: duplicate symbol: rustsecp256k1_v0_12_nonce_function_rfc6979
          >>> defined at secp256k1.h:638 (depend/secp256k1/include/secp256k1.h:638)
          >>>            4d6b2bbe68124288-lax_der_parsing.o:(rustsecp256k1_v0_12_nonce_function_rfc6979) in archive ~/rust-secp256k1/target/debug/deps/libsecp256k1_sys-b1b59c933f23d7ba.rlib
          >>> defined at secp256k1.h:638 (depend/secp256k1/src/../include/secp256k1.h:638)
          >>>            fce6141bfa9bf74c-secp256k1.o:(.data.rel.ro.local.rustsecp256k1_v0_12_nonce_function_rfc6979+0x0) in archive ~/rust-secp256k1/target/debug/deps/libsecp256k1_sys-b1b59c933f23d7ba.rlib

          rust-lld: error: duplicate symbol: rustsecp256k1_v0_12_nonce_function_default
          >>> defined at secp256k1.h:641 (depend/secp256k1/include/secp256k1.h:641)
          >>>            4d6b2bbe68124288-lax_der_parsing.o:(rustsecp256k1_v0_12_nonce_function_default) in archive ~/rust-secp256k1/target/debug/deps/libsecp256k1_sys-b1b59c933f23d7ba.rlib
          >>> defined at secp256k1.h:641 (depend/secp256k1/src/../include/secp256k1.h:641)
          >>>            fce6141bfa9bf74c-secp256k1.o:(.data.rel.ro.local.rustsecp256k1_v0_12_nonce_function_default+0x0) in archive ~/rust-secp256k1/target/debug/deps/libsecp256k1_sys-b1b59c933f23d7ba.rlib
          collect2: error: ld returned 1 exit status


error: could not compile `secp256k1` (lib test) due to 1 previous error

---

What I've tried:
I created a patch, nymius/rust-secp256k1@6d0b801, compiling against the latest working commit, 1b1fc09341c956e8918adba1eeaa43b47d73ea84, and reviewed the symbols created:

$ nm -A ~/rust-secp256k1/target/debug/deps/libsecp256k1_sys-b1b59c933f23d7ba.rlib | rg "context_no_precomp"
nm: lib.rmeta: no symbols
~/rust-secp256k1/target/debug/deps/libsecp256k1_sys-b1b59c933f23d7ba.rlib:secp256k1_sys-b1b59c933f23d7ba.5j2437td37q4axursxx0h9100.12jl1g7.rcgu.o: U rustsecp256k1_v0_12_context_no_precomp
~/rust-secp256k1/target/debug/deps/libsecp256k1_sys-b1b59c933f23d7ba.rlib:fce6141bfa9bf74c-secp256k1.o:0000000000000000 D rustsecp256k1_v0_12_context_no_precomp

And another patch, nymius/rust-secp256k1@4df7ac6, compiling against the first failing commit, 432ac57705b8e2f6a5874095214c443f1f8ea9bf, and reviewed the symbols as well:

$ nm -A ~/rust-secp256k1/target/debug/deps/libsecp256k1_sys-b1b59c933f23d7ba.rlib | rg "context_no_precomp"
nm: lib.rmeta: no symbols
~/rust-secp256k1/target/debug/deps/libsecp256k1_sys-b1b59c933f23d7ba.rlib:secp256k1_sys-b1b59c933f23d7ba.5j2437td37q4axursxx0h9100.1kpnmkg.rcgu.o:                 U rustsecp256k1_v0_12_context_no_precomp
~/rust-secp256k1/target/debug/deps/libsecp256k1_sys-b1b59c933f23d7ba.rlib:4d6b2bbe68124288-lax_der_parsing.o:0000000000000000 R rustsecp256k1_v0_12_context_no_precomp
~/rust-secp256k1/target/debug/deps/libsecp256k1_sys-b1b59c933f23d7ba.rlib:fce6141bfa9bf74c-precomputed_ecmult_gen.o:0000000000000000 R rustsecp256k1_v0_12_context_no_precomp
~/rust-secp256k1/target/debug/deps/libsecp256k1_sys-b1b59c933f23d7ba.rlib:fce6141bfa9bf74c-precomputed_ecmult.o:0000000000000000 R rustsecp256k1_v0_12_context_no_precomp
~/rust-secp256k1/target/debug/deps/libsecp256k1_sys-b1b59c933f23d7ba.rlib:fce6141bfa9bf74c-secp256k1.o:0000000000000000 D rustsecp256k1_v0_12_context_no_precomp

Previous to the failing commit, const <type> *<var> was being translated in a single common symbol, but after adding the const qualifier to the pointer, there are three read only repeated symbols

I've found that by setting SECP256K1_API to extern, nymius/rust-secp256k1@f949266 or removing it completely (letting libsecp256k1 set it by itself), the issue disappears, and the symbols get unified:

$ nm -A ~/rust-secp256k1/target/debug/deps/libsecp256k1_sys-b1b59c933f23d7ba.rlib | rg "context_no_precomp"
nm: lib.rmeta: no symbols
~/rust-secp256k1/target/debug/deps/libsecp256k1_sys-b1b59c933f23d7ba.rlib:secp256k1_sys-b1b59c933f23d7ba.5j2437td37q4axursxx0h9100.0u8ohs8.rcgu.o: U rustsecp256k1_v0_12_context_no_precomp
~/rust-secp256k1/target/debug/deps/libsecp256k1_sys-b1b59c933f23d7ba.rlib:fce6141bfa9bf74c-secp256k1.o:0000000000000000 D rustsecp256k1_v0_12_context_no_precomp

---

More context:
Originally I thought the issue was related to SECP256K1_API setting, as in later commits of libsecp256k1 it caused other issues that piled up.

Now I'm not sure it is the source of this original error.

Still, SECP256K1_API setting seems to have been set by the wrong reasons], ee1103a as the use of Some("") is still setting the variable with "". The right approach to not set it is to remove it, rather than giving a None or Some("") value. However, I'm not sure what's the best approach to visibility from the rust standing point.
From my short understanding, looking at this comment about downstream uses of the API in libsecp256k1 and the latest refactors on visibility in libsecp256k1, bitcoin-core/secp256k1#1696, we shouldn't be touching this variable, and let libsecp256k1 set it by itself.

[nymius]

As this isn't already on the master branch, but is in the following natural release of libsecp256k1, the first move should be to update to libsecp256k1@v0.7.0 version, and fix the issue there.

[apoelstra]

I think SECP256K1_API is a total red herring. That symbol does not occur in any file that this library compiles so it has no effect whatsoever whether we set it or not. If it did appear then we would need to set it or else the code would not compile, since the library itself does not define it. But we don't.

Maybe things were different back when we merged #289 or maybe Matt was just mistaken. But right now it has no effect whatsoever.

Thanks very much for bisecting to the offending commit. The problem here is that the definition in secp256k1.c has changed. (The definition in secp256k1.h, which has SECP256K1_API on it, is totally irrelevant.) The definition no longer matches the patch secp256k1-sys/depend/secp256k1.h.patch that we use to remove this object. (I think. I haven't tested this yet.)

vendor-libsecp.sh should have failed for you because of this patch -- how are you testing different libsecp versions?

This definition is renamed by our vendoring code to rustsecp256k1_v0_12_context_static. In #876 this is v0_13.

[apoelstra]

Yeah, a first step would be to just update master to use 0.7.0 and see if the problem still appears.

[nymius]

That symbol does not occur in any file that this library compiles so it has no effect whatsoever whether we set it or not.

I'm not understanding this. secp256k1-sys is compiling secp256k1.c, which includes secp256k1.h. This doesn't mean the pre-processor is going to dump the content of secp256k1.h into secp256k1.c before compiling? and preprocessor directives are going to be replaced as well in that stage? making secp256k1.c compile whatever secp256k1.h transformed into, including the definition of SECP256K1_API?

vendor-libsecp.sh should have failed for you because of this patch -- how are you testing different libsecp versions?

Indeed, it failed, but knowing the content of the offending commit in libsecp256k1 I applied the right changes in secp256k1-sys/depend/secp256k1/include/secp256k1.h, then triggered the duplicated symbol.

This definition is renamed by our vendoring code to rustsecp256k1_v0_12_context_static. In #876 this is v0_13.

As this wasn't exposing any API breaking change to rust-secp256k1 (the only consumer?) the major version is still 0, and minor versions may include patch changes, I thought v0.13.0 was the right bump after updating the underlying C lib.

[apoelstra]

which includes secp256k1.h

Huh. Indeed it does. Now I don't understand how your change to un-define SECP256K1_API can compile.

As this wasn't exposing any API breaking change to rust-secp256k1 (the only consumer?) the major version is still 0, and minor versions may include patch changes, I thought v0.13.0 was the right bump after updating the underlying C lib.

You were correct for the wrong reasons :P. rust-secp256k1 is not necessarily the only consumer of the secp256k1-sys library. Any update to the C code requires renaming all the symbols, which is a breaking change to secp256k1-sys (the rename must be done, because two distinct versions of the C code with overlapping symbols will at-best refuse to compile together and at-worst be undefined behavior when compiled together).

Then because rust-secp256k1 re-exports symbols from secp256k1-sys this is also a breaking change to rust-secp256k1, but we don't need to worry about that in #879.

However Rust has a special semver rule that when we are in the 0.x.y version spectrum, x is the "major version" and y is the "minor version" and there is no "patch version". Semver itself says that the 0.x span is a free-for-all so this additional rule is permissible. So your bump from 0.12.x to 0.13.x did indicate a semver breaking change.

[nymius]

Huh. Indeed it does. Now I don't understand how your change to un-define SECP256K1_API can compile.

I understand it compiles because of this preprocessing block inside secp256k1.h (included in secp256k1.c).

[apoelstra]

Whoah, I never noticed that block before. (Well, I also didn't realize that we were pulling in secp256k1.h before..) I think it winds up defining SECP256K1 to extern.