Compilation on RHEL/CentOS 7 fails on pkg-config

[dmc5179]

When building a tool that uses this package I get the following error:

pkg-config --cflags -- gpgme
Package gpgme was not found in the pkg-config search path.
Perhaps you should add the directory containing `gpgme.pc'
to the PKG_CONFIG_PATH environment variable
No package 'gpgme' found

Looking at RHEL and CentOS 7 there doesn't appear to be a pkg config file for gpgme.

Is there a way to resolve the issue so this module can find the cflags?

[proglottis]

@dmc5179 that's a pain.

You probably need to revert this https://github.com/proglottis/gpgme/pull/35/files

I'm not sure what we could do as a permanent solution. It seems some systems require pkg-config and others require LD_FLAGS to be set manually.

[proglottis]

Well one option would be to use the version before I changed the build -- https://pkg.go.dev/github.com/proglottis/gpgme@v0.1.1

[dmc5179]

@proglottis Thanks for your quick response. Switching to that version does get me past the pkgconfig error but ends with a different error below. I'm afraid this might be one of those rabbit holes that doesn't end and its just not going to run on RHEL 7 without a lot of work.

vendor/github.com/proglottis/gpgme/data.go:187:12: could not determine kind of name for C.gogpgme_data_seek
vendor/github.com/proglottis/gpgme/data.go:53:53: could not determine kind of name for C.gpgme_off_t
cgo: 
gcc errors for preamble:
In file included from vendor/github.com/proglottis/gpgme/data.go:6:0:
./go_gpgme.h:15:1: error: unknown type name 'gpgme_off_t'
 extern gpgme_off_t gogpgme_data_seek(gpgme_data_t dh, gpgme_off_t offset, int whence);
 ^
./go_gpgme.h:15:55: error: unknown type name 'gpgme_off_t'
 extern gpgme_off_t gogpgme_data_seek(gpgme_data_t dh, gpgme_off_t offset, int whence);

Assuming that this is just a rabbit hole then we can close this issue.

[proglottis]

@dmc5179 it does sound like a bit of a rabbit hole. Seems your version of gpgme is very old.

In any case I found this comment that might help with that specific error Azure/ARO-RP#301 (comment)

No guarantees here though. It's possible we're using other types/constants/functions newer than your version of gpgme as well.

Ultimately I don't think there's a way to support all versions of gpgme via CGO without having separate libraries.