configure finds zlib but pillow does not

[mkoeppe]

https://groups.google.com/d/msg/sage-support/vS2CZd_kEHA/f1VaXUQhAQAJ

In complete analogy to
#29448 (configure finds libpng but matplotlib does not)

See also:

• generate libpng.pc, zlib.pc if needed #28906 generate libpng.pc, zlib.pc if needed

Depends on #30185

CC: @dimpase @orlitzky @jhpalmieri

Component: build: configure

Issue created by migration from https://trac.sagemath.org/ticket/30103

[dimpase]

comment:2

I don't see how this is in analogy to #29448

With zlib we don't use pkg-config - so something really goes bad in pillow.

[orlitzky]

comment:3

Pillow's build system is a half-baked reimplementation of autotools in python. It tries and fails to guess the system library location, whereas AC_CHECK_LIB actually compiles and links something, so it doesn't need to guess.

The first thing we should do is upgrade to the latest version of pillow so that we aren't completely wasting our time. Then the best solution would be for them to adopt a real build system reimplement AC_CHECK_LIB in their python script. Trying to fix the list of guessed locations isn't a good long term solution because it's guaranteed to find the wrong libraries if you check e.g. /usr/lib before /usr/lib64 on a multilib system. All you really want to know is if you can compile something with -lz, so autotools has the right idea.

[mkoeppe]

comment:4

+1 on upgrading pillow first.

[mkoeppe]

comment:5

Replying to @dimpase:

I don't see how this is in analogy to #29448

With zlib we don't use pkg-config - so something really goes bad in pillow.

Well, pillow uses pkg-config to find zlib, as you can see in the bug report:

[pillow-5.3.0.p0] Looking for `zlib` using pkg-config.
[pillow-5.3.0.p0] Looking for zlib

[mkoeppe]

Branch: u/mkoeppe/configure_finds_zlib_but_pillow_does_not

[mkoeppe]

Commit: 8eb7aa9

[mkoeppe]

New commits:

8eb7aa9

build/pkgs/pillow: Update to 7.2.0

[mkoeppe]

comment:8

7.2.0 still uses the same approach for finding its libraries.

Since it checks each library using pkgconfig first, Dima's approach of generating fake pkgconfig files (from the abandoned ticket #28906) could be a solution that would not require patching pillow.

[orlitzky]

comment:9

I wonder why pillow's pkg-config isn't finding zlib in this case. I think the reporter is using Gentoo, and we install zlib.pc. In fact everyone should be installing zlib.pc since 2012 or so.

[dimpase]

comment:10

probably his PKG_path - whatever it is called, ismiconfigured.

[mkoeppe]

comment:11

Moved the pillow upgrade to #30185

[mkoeppe]

Dependencies: #30185

[mkoeppe]

Changed branch from u/mkoeppe/configure_finds_zlib_but_pillow_does_not to none

[mkoeppe]

Changed commit from 8eb7aa9 to none

[mkoeppe]

comment:15

Moving to 9.4, as 9.3 has been released.