Provide ruby.exe so it's a drop-in replacement for MRI

[eregon]

See jruby/jruby#6042 (comment)

Currently it's not obvious how to make ruby ... work on Windows.
On Unix this is usually done easily with ln -s jruby ruby, but on Windows the only way I could find is to create a ruby.bat with:

@ECHO OFF
@"%~dp0jruby.exe" %*

(I also tried mklink on Windows, that doesn't work)

It would be nice if this could be simplified and e.g. JRuby already ships with that ruby.bat and ruby files.

gem, rake, etc already conflict with MRI binaries so the only way to use a Ruby is to add it to PATH anyway. Not having something for ruby ... means there is a the danger to use MRI for that one, but not for other commands such as gem and rake, which is never intended.

[eregon]

Having a 64-bit jruby.exe launcher would also be valuable:
jruby/jruby#6042 (comment)

[eregon]

@headius This became a problem again, see ruby/setup-ruby#18 (comment)

I'll copy the comments here for convenience:
Various issues here, once again with how to provide a ruby alias for jruby that works in both PowerShell and Bash:

• ruby -v in bash just fails on Windows if there is only ruby.bat: https://github.com/eregon/setup-ruby-test/runs/433780474?check_suite_focus=true
• cp jruby.sh ruby fails because JRuby's .sh launcher is broken on Windows in JRuby 9.2.9.0: https://github.com/eregon/setup-ruby-test/runs/433786338?check_suite_focus=true
• cp jruby.exe ruby.exe fails in PwSh: https://github.com/eregon/setup-ruby-test/runs/433787577?check_suite_focus=true
• cp jruby.bash ruby kind of works but incorrectly deals with double quotes ("), which is fairly confusing: https://github.com/eregon/setup-ruby-test/runs/433791906?check_suite_focus=true
  MRI handles the double quotes fine: https://github.com/eregon/setup-ruby-test/runs/433791899?check_suite_focus=true

Could we have a ruby.exe or make cp jruby.exe ruby.exe work?
.bat files are ignored in Bash on Windows.
So I think only .exe files work in both PwSh and Bash.

[eregon]

Here are the executables provided on MRI built by RubyInstaller2:

$ ls -l rubyinstaller-2.5.7-1-x64/bin
total 3.3M
-rwxr-xr-x. 1 eregon eregon 4.8K Oct  2 00:54 erb
-rw-r--r--. 1 eregon eregon 4.9K Oct  2 00:54 erb.cmd
-rwxr-xr-x. 1 eregon eregon  546 Oct  2 00:54 gem
-rw-r--r--. 1 eregon eregon  688 Oct  2 00:54 gem.cmd
-rwxr-xr-x. 1 eregon eregon  190 Oct  2 00:54 irb
-rw-r--r--. 1 eregon eregon  360 Oct  2 00:54 irb.cmd
-rw-r--r--. 1 eregon eregon  729 Oct  2 00:54 rake
-rw-r--r--. 1 eregon eregon  153 Oct  2 00:54 rake.cmd
-rwxr-xr-x. 1 eregon eregon  938 Oct  2 00:54 rdoc
-rw-r--r--. 1 eregon eregon 1.1K Oct  2 00:54 rdoc.cmd
-rwxr-xr-x. 1 eregon eregon  188 Oct  2 00:54 ri
-rw-r--r--. 1 eregon eregon  330 Oct  2 00:54 ri.cmd
-rw-r--r--. 1 eregon eregon  694 Oct  2 00:54 ridk.cmd
-rw-r--r--. 1 eregon eregon  870 Oct  2 00:54 ridk.ps1
drwxr-xr-x. 2 eregon eregon 4.0K Oct  2 00:54 ruby_builtin_dlls
-rwxr-xr-x. 1 eregon eregon  35K Oct  2 00:54 ruby.exe
-rwxr-xr-x. 1 eregon eregon  35K Oct  2 00:54 rubyw.exe
-rw-r--r--. 1 eregon eregon  312 Oct  2 00:54 setrbvars.cmd
-rwxr-xr-x. 1 eregon eregon 3.1M Oct  2 00:54 x64-msvcrt-ruby250.dll

So having a ruby.exe seems the key.
And cp jruby.exe ruby.exe doesn't work currently unfortunately.

[headius]

Is this only affecting Windows?

Most of the time we do not want to depend on the native launcher when the bash script works. If we could get rid of the native launcher we would, but it's needed on a few platforms (Darwin, Solaris) that don't support putting scripts into shebang lines.

[headius]

FWIW I would be fine with JRuby publishing ruby as the primary executable (bash or native) with jruby just a script that launches it. There's almost never a good reason to have both jruby and an unrelated ruby in PATH.

[eregon]

Yes, it's only on Windows.
In PowerShell, the bash script would never be picked by ruby ....
So we need a reliable way to have ruby ... work in PowerShell for JRuby in Windows CIs.

The Bash script should also work with Bash on Windows, but currently it doesn't deal with quotes correctly.

My current workaround is copying the jruby Bash script to ruby, and adding ruby.bat but it's not perfect and it feels hacky I have to mess with the launchers manually:
https://github.com/ruby/ruby-builder/blob/b4e83abd2f97c1374f0e54cde134b359947df550/.github/workflows/build.yml#L108-L111

Could we maybe fix whatever in jruby.exe assumes the executable to be named jruby.exe? Then at least we could copy it to ruby.exe and that would hopefully work.
Even better would be to provide ruby.exe out of the box.

[headius]

A trivial fix would be to have the launcher build and install both jruby.exe and ruby.exe.

Someone's going to have to get the launcher updated to support our .java_opts files very soon so this should get fixed at the same time.

[eregon]

Another reason is the latest jruby snapshot currently generates this for bundle.bat after gem install bundler:

@ECHO OFF
@"%~dp0ruby.exe" "%~dpn0" %*

Which is ruby.exe, not jruby.exe, so bundle probably doesn't work at all on Windows with the latest jruby snapshot:
https://oss.sonatype.org/content/repositories/snapshots/org/jruby/jruby-dist/9.2.10.0-SNAPSHOT/jruby-dist-9.2.10.0-20200214.210645-79-bin.tar.gz

https://github.com/ruby/jruby-dev-builder/runs/448860418

[headius]

We do not generate those stubs... it's almost certainly something that has changed in RubyGems.

[deivid-rodriguez]

This is rubygems issue rubygems/rubygems#2873 (a 3.0 specific regression caused by rubygems/rubygems#2119). It was fixed by rubygems/rubygems#2876, which is present in the latest rubygems but it was never backported to rubygems 3.0 (although it's been scheduled for backport to rubygems 3.0.7).

@hsbt Do you still intend to release rubygems 3.0.7 including rubygems/rubygems#2876?