Known Issues
As discussed in issue 249 and elsewhere, you may encounter problems when not using the mount_on option in a mounted uploader. Due to bug/feature/unexpected behavior in ActiveRecord, when loading records from database using associations it might happen that ActiveRecord tries to assign String value to uploader column. If this happens you need to rename database column (for example use file_identifier instead of file) and specify new name as mount_on option when mounting uploader.
As discussed in issue 75 and elsewhere, when uploading a new file over another existing file in a mounted uploader, previously stored files will not be removed. Pull requests that aim to solve this problem are most welcome.
If you get an error such as "Attachment failed to be processed" ensure that you have installed the relevant image manipulation library before installing the associated gem.
Read this "Stack Overflow page":http://stackoverflow.com/questions/2838307/why-is-this-rmagick-call-generating-a-segmentation-fault and try uninstalling any prexisting installations and deleting your cache.
brew remove imagemagick
brew --cache imagemagick
brew install -f imagemagick --disable-openmp