Bug#798626: perl: -V lies about -Duseshrplib

[Tom Lane]

Hi folks,

I'd just like it to be on the record that this change broke the build
process for PostgreSQL.

The immediate symptom is that "perl -V:useshrplib" no longer reports
true, which causes our configure script to spit up, figuring that it is
not going to be able to find a shared-library libperl to link against.
We have determined after some experimentation that if we drop that
safety check then we will still get a valid build on Debian, but it's
fairly nervous-making that we will no longer be able to have that
sanity check for other platforms.  Also, from what I understand of
what you changed, it seems like there is a nontrivial risk that
"perl -MExtUtils::Embed -e ldopts" would report linker flags that
lead to linking in a static version of libperl.  That is likely
to fail outright on some hardware (depending on how the static
library was built); and if it doesn't fail, it will result in
libperl.a becoming embedded in the calling package, which I surely
hope is against your distribution policies.

So: you can stick with this, or not, but you are risking bad
consequences for Postgres and for other consumers of libperl.so.

You can find the Postgres mailing list discussion about this at

https://www.postgresql.org/message-id/flat/20200606222017.GA2564110%40rfd.leadboat.com

			regards, tom lane