CMake: fix detection of SoundTouch pkgconfig file and version

[Be-ing]

I noticed this bug after copying this module to Tenacity.

[coveralls]

Pull Request Test Coverage Report for Build 1134039623

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💛 - Coveralls

[daschuer]

The version constrain does not seem to work:

-- Found SoundTouch: /usr/lib/x86_64-linux-gnu/libSoundTouch.so  
-- Linking libSoundTouch dynamically

Tested in a fresh build directory and SoundTouch 1.9.2 installed.

If I remove the QUIET flag it prints;

-- Checking for module 'soundtouch>=2.1.1'
--   Requested 'soundtouch >= 2.1.1' but version of SoundTouch is 1.9.2

[daschuer]

This does not yet work as intended.

[uklotzde]

$ pkgconf --list-all | grep -i soundtouch
soundtouch                     SoundTouch - SoundTouch is an open-source audio processing library for changing the Tempo, Pitch and Playback Rates of audio streams or files
libSoundTouch                  SoundTouch - SoundTouch is an open-source audio processing library for changing the Tempo, Pitch and Playback Rates of audio streams or files
soundtouch-1.0                 SoundTouch - SoundTouch is an open-source audio processing library for changing the Tempo, Pitch and Playback Rates of audio streams or files

@daschuer Please post the output on the affected system.

@Be-ing Did you try to use libSoundTouch instead of soundtouch?

[uklotzde]

All 3 variants on Fedora 34:

-- Checking for module 'SoundTouch>=2.1.1'
--   Package 'SoundTouch', required by 'virtual:world', not found
-- Found SoundTouch: /usr/lib64/libSoundTouch.so  
-- Linking libSoundTouch dynamically

-- Checking for module 'soundtouch>=2.1.1'
--   Package dependency requirement 'soundtouch >= 2.1.1' could not be satisfied.
Package 'soundtouch' has version '2.0.0', required version is '>= 2.1.1'
-- Found SoundTouch: /usr/lib64/libSoundTouch.so  
-- Linking libSoundTouch dynamically

-- Checking for module 'libSoundTouch>=2.1.1'
--   Package dependency requirement 'libSoundTouch >= 2.1.1' could not be satisfied.
Package 'libSoundTouch' has version '2.0.0', required version is '>= 2.1.1'
-- Found SoundTouch: /usr/lib64/libSoundTouch.so  
-- Linking libSoundTouch dynamically

None seems to be correct.

[uklotzde]

The soundtouch.pc/libSoundTouch.pc files in Fedora 34 are outdated and advertise Version: 2.0.0 🙈

[uklotzde]

The current package name SoundTouch is wrong, both soundtouch or libSoundTouch should work.

[uklotzde]

The wrong version number is caused by an outdated configure.ac. This has been fixed for the new version 2.3.0.

[uklotzde]

soundtouch is the official package name according to the build spec in Fedora:

# pkgconfig compat links for compat with older (API compatible) releases
# dunno why upstream keeps changing the pkgconfig name
# Update 2016-02-13: now looks like that is soundtouch.pc without version
ln -s soundtouch.pc %{buildroot}%{_libdir}/pkgconfig/libSoundTouch.pc
ln -s soundtouch.pc %{buildroot}%{_libdir}/pkgconfig/soundtouch-1.0.pc

[uklotzde]

https://src.fedoraproject.org/rpms/soundtouch/pull-request/2

[daschuer]

On Ubuntu Groovy I have this:

pkg-config --list-all | grep -i soundtouch
soundtouch                     SoundTouch - SoundTouch is an open-source audio processing library for changing the Tempo, Pitch and Playback Rates of audio streams or files

[daschuer]

The found version is not checked, because it is not passed too find_package_handle_standard_args like here:

mixxx/cmake/modules/Findhidapi.cmake

Line 100 in 50b40ab

VERSION_VAR hidapi_VERSION

[uklotzde]

I can confirm that the package name soundtouch is correct.

The version detection works for SoundTouch 2.1.2 and newer. It was broken for SoundTouch 2.1.0 and 2.1.1.

Unless we fix this bug on our side Fedora and any other distribution will not be able to use the system library for Mixxx and always link the bundled version statically.

@daschuer Please work with upstream Debian/Ubuntu if they ship an outdated package as we did for Fedora.

[uklotzde]

@Be-ing Please change the target branch to 2.3. Done

[uklotzde]

We could also increase the required version number to 2.1.2 due to the buggy package configuration of SoundTouch 2.1.1.

[uklotzde]

Ubuntu 20.04: 2.1.2
Ubuntu 18.04: 1.9.2

It doesn't matter why the version detection for 18.04 fails, SoundTouch is too old anyway.

[daschuer]

@daschuer Please work with upstream Debian/Ubuntu if they ship an outdated package as we did for Fedora.

The most recent Ubuntu Impish 21.10 ships SoundTouch 2.2 which is identified as 2.2 in the lower case pc file. The Name in the pc file is upper case. Both matches the upstream repro. So I it looks like everything is correct for Ubuntu.

I can confirm that only the lower case lookup works:

pkg-config soundtouch --modversion
2.1.2

I don't think we have an issue on Fedora, because even though it falsely identifies itself at 2.1.1 it still meets our requirements.

[daschuer]

The pending issue here, preventing the merge, is that the version constrains in the pkg-config call is bypassed by the find_library() later call #4209 (comment)

[uklotzde]

Requiring the broken version 2.1.1 is pointless, because it will never be found.

[uklotzde]

Ubuntu 20.04 build artifact is linked dynamically:

ldd /tmp/mixxx | grep -i SoundTouch
libSoundTouch.so.1 => not found

@daschuer So what's your issue here? The appended .1 version of the .so file that should actually be .2? Fedora packaging includes a patch for this that has been submitted upstream now and is included in SoundTouch 2.3.1.

[uklotzde]

Unfortunately 18.04 is not built even after switching the base branch.

[uklotzde]

No issues on Fedora with SoundTouch 2.1.2:

ldd mixxx | grep SoundTouch
libSoundTouch.so.2 => /lib64/libSoundTouch.so.2 (0x00007f54ec5a4000)

[daschuer]

Requiring the broken version 2.1.1 is pointless, because it will never be found.

We require soundtouch>=2.1.1which is found a s 2.1.2 or whatever, so there is no issue.

2.1.1 is our version in the lib folder. It looks odd if we require a higher version that we provide.
Once all our targets provide this or a higher version we can remove sound touch from our lib folder.

@daschuer So what's your issue here?

The issue is that requiring a version in the OPTIONAL pkg_check_modules branch is pointless if it is not also checked in the final find_package_handle_standard_args().

That's all.

[uklotzde]

Let's please merge this simple fix and then you could provide a follow-up PR.

[daschuer]

We can't mege this to 2.3 because it is a regression for Ubuntu 18.04.

It is easy to make this megeable, see my comment where I have already outlined the solution:
#4209 (comment)

[Be-ing]

I moved the version check from the pkgconfig call, which didn't do anything because of the find_library executed in all cases, to the root CMakeLists.txt. Like hidapi, I implemented a fallback of reading the version from SoundTouch.h in case pkgconfig is not available.

[uklotzde]

CI build succeeded. @daschuer Ready now?

[daschuer]

LGTM, Thank you. It is working as desired on Ubuntu Bionic and Groovy.