Blosc/python-blosc2

distributed `blosc2.pc` has wrong prefix

nega0 opened this issue · 7 comments

nega0 commented

The distributed blosc2.pc includes the wrong prefix. This obviously complicates anything that tries to use pkg-config to detect blsoc2. Basically whatever temporary directory python-blosc2 is installed to during the build process becomes the prefix.

The two wheels I've checked have:

  • macOS-arm64: prefix=/Users/runner/work/python-blosc2/python-blosc2/_skbuild/macosx-11.0-arm64-3.11/cmake-install
  • linux-x86_64: prefix=/project/_skbuild/linux-x86_64-3.10/cmake-install

When installing from source you get something akin to:

  • prefix=/Users/nega/Downloads/python-blosc2/_skbuild/macosx-13.0-arm64-3.11/cmake-install

Three ways I see to address this issue are

  1. during the build process, edit the build2.pc after its creation
  2. take advantage of DESTDIR during the build of c-blosc2
  3. remove build2.pc outright

See also PyTables/PyTables#998

The following is a demonstration of installing python-blosc2 into a clean virtual env creatively called "blosc2".

❯ python -m venv blosc2

❯ . blosc2/bin/activate

blosc2 ❯ pip3 install --upgrade blosc2
[... 8< ...]
Successfully installed blosc2-2.2.1 markdown-it-py-2.2.0 mdurl-0.1.2 msgpack-1.0.5 ndindex-1.7 numpy-1.24.3 py-cpuinfo-9.0.0 pygments-2.15.1 rich-13.3.5

blosc2 ❯ find ./blosc2 -name blosc2.pc
./blosc2/lib/pkgconfig/blosc2.pc

blosc2 ❯ cat ./blosc2/lib/pkgconfig/blosc2.pc
prefix=/Users/runner/work/python-blosc2/python-blosc2/_skbuild/macosx-11.0-arm64-3.11/cmake-install
exec_prefix=${prefix}
libdir=${exec_prefix}/lib
sharedlibdir=${libdir}
includedir=${prefix}/include

Name: blosc2
Description: A blocking, shuffling and lossless compression library
URL: https://blosc.org/
Version: 2.9.1

Requires:
Libs: -L${libdir} -L${sharedlibdir} -lblosc2
Cflags: -I${includedir}

blosc2 ❯ find blosc2 -name libblosc2\*
blosc2/lib/libblosc2.2.dylib
blosc2/lib/libblosc2.a
blosc2/lib/libblosc2.2.9.1.dylib
blosc2/lib/libblosc2.dylib
nega0 commented

CMAKE_INSTALL_PREFIX should respond to DESTDIR. I didn't look specifically what python-blosc2 is doing, but if you were staging a general CMake project for distribution you'd do something like

$ cmake -DCMAKE_INSTALL_PREFIX=/opt/project ../src
$ make DESTDIR=/scratch/staging_area install

and it will install to /scratch/staging_area/opt/project/{lib,bin,share,etc,etc} you can then tar it up or whatever, and paths will be correct for the final destination. there's a bit more to it than that.

Additionally, CMake can generate pkg-config *.pc files. Maybe c-blosc2 should be taking advantage of that instead of just running blosc2.pc through configure_file().

bnavigator commented

prefix=@CMAKE_INSTALL_PREFIX@ for a library.pc.in file is a common pattern though. Maybe scikit-build should split up their setting into CMAKE_INSTALL_PREFIX and DESTDIR.

cc @henryiii

bnavigator commented

OTOH, how is a python build backend supposed to know where a wheel is to be installed? The shipped .pc.in in the wheel will have a hardcoded prefix but the installation could be in any PYTHONPATH (venv, system, user, ...). Thus, a wheel should not have the pkconfig file at all.

nega0 commented

Thus, a wheel should not have the pkconfig file at all.

Aggreed

FrancescAlted commented

Thus, a wheel should not have the pkconfig file at all.

Aggreed

Sounds good to me too. Any idea on how to prevent blosc2.pc to go in the wheel? Happy to remove it.

nega0 commented

👍