* Vít Ondruch:
Since you are digging into this and AFAIK you are involved with
toolchains, this reminds me this dreaded issue:
In short, various languages, such as Ruby embeds the build time
options and reuse them for build of extensions. And I wonder, would it
be possible to generalize this e.g. into some tool, which would set
the environment variables and would be usable outside of rpmbuild?
We have added %extension_… macros for the options that are safe to
hard-code. But it doesn't solve the actual issue.
The problem is not that it is difficult to get the flags, the issue is
that we simply can't get the extension builders to move away from
If we add another mechanism, it will be as Fedora-specific as
`rpm --eval %build_cflags` is today.