meson: Dependency python3-libnvme not found

[tbzatek]

nvme-stas/test/meson.build

Line 9 in cf18029

libnvme_dep = dependency('python3-libnvme', fallback: ['libnvme', 'libnvme_dep'], version : '>= 1.2', required: false) # Only required to run the tests

A minor issue that I came across when packaging -rc5 in Fedora: the python3-libnvme dependency as in term of a pkg-config module is not provided by the upstream libnvme tarball and is not (typically) present in Fedora/RHEL either. Using the 2.0-rc5 tarball that has the following snippet (that was later changed by commit 8d691bd) I still get a meson failure even though the fallback argument is specified and which somewhat gets ignored by meson:

    #libnvme_dep = dependency('python3-libnvme', fallback : ['libnvme', 'libnvme_dep'], version : '>= 1.2')
    libnvme_dep = dependency('python3-libnvme', fallback : ['libnvme', 'libnvme_dep'])

Found pkg-config: /usr/bin/pkg-config (1.8.0)
Found CMake: /usr/bin/cmake (3.24.1)
Run-time dependency python3-libnvme found: NO (tried pkgconfig and cmake)
Looking for a fallback subproject for the dependency python3-libnvme

test/meson.build:15:4: ERROR: Automatic wrap-based subproject downloading is disabled

With the above mentioned change on git master I still get a non-fatal meson failure:

Found pkg-config: /usr/bin/pkg-config (1.8.0)
Found CMake: /usr/bin/cmake (3.24.1)
Run-time dependency python3-libnvme found: NO (tried pkgconfig and cmake)
Looking for a fallback subproject for the dependency python3-libnvme
Automatic wrap-based subproject downloading is disabled
Subproject  libnvme is buildable: NO (disabling)
Dependency python3-libnvme from subproject libnvme found: NO (subproject failed to configure)

I've changed the python3-libnvme in our builds to plain libnvme in the meantime, not sure what was your original intention though. But again, this is just a very minor glitch.

[martin-belanger]

Have you tried the latest code? This should have been fixed by #267 which came after 2.0-rc5.

[martin-belanger]

BTW, this dependency is only needed to run the tests. We added required: false to the dependency, which should solve this issue.

[tbzatek]

I did, it's not fatal anymore but the fallback doesn't work either.

[tbzatek]

Oh, I see, the meson fallback option is used to build a subproject in case of an missing dependency. That's obviously disabled within buildsystem env, forbidding internet access or embedding libraries in general. In any case the python3-libnvme pkg-config module requirement is an issue.

[martin-belanger]

Are you running the unit tests as part of the buildsystem? If you are not running the tests, then it's not an issue.

The tests depend on python3-libnvme being installed. Or maybe the issue is that meson cannot find Python packages because they don't usually come with a .pc file. Is that the issue?

There's another way I can check for the presence of python3-libnvme, but it's not going to be a meson approach, and if the library is missing the tests will be skipped.

I'm open to suggestions.

[martin-belanger]

Fixed by #275

@tbzatek - Please check that the above pull request fixes the issue. Thanks.

[tbzatek]

Nope, that made things actually worse. The test subdir and its meson.build file suggests that this target is always enabled, failing the basic build:

$ meson --wrap-mode=nodownload -Dman=true -Dhtml=true .build
The Meson build system
Version: 0.63.2
Source dir: /tmp/nvme-stas
Build dir: /tmp/nvme-stas/.build
Build type: native build
Project name: nvme-stas
Project version: 2.0
Host machine cpu family: x86_64
Host machine cpu: x86_64
Program python3 (lxml) found: YES (/usr/bin/python3) modules: lxml
Configuring nvme-stas.spec using configuration
Configuring .coveragerc using configuration
Configuring coverage.sh using configuration
Configuring defs.py using configuration
Configuring __init__.py using configuration
Configuring org.nvmexpress.staf.conf using configuration
Configuring org.nvmexpress.stac.conf using configuration
Configuring stafd.service using configuration
Configuring stacd.service using configuration
Configuring stas-config.target using configuration

test/meson.build:13:0: ERROR: Automatic wrap-based subproject downloading is disabled

I guess the --wrap-mode=nodownload meson argument should be crucial for a final test before making a release. It's a default of many distribution buildsystems. We don't need to run unit tests during the build. For the record, this is how the default Fedora meson command expansion looks like:

/usr/bin/meson --buildtype=plain --prefix=/usr --libdir=/usr/lib64 --libexecdir=/usr/libexec --bindir=/usr/bin --sbindir=/usr/sbin --includedir=/usr/include --datadir=/usr/share --mandir=/usr/share/man --infodir=/usr/share/info --localedir=/usr/share/locale --sysconfdir=/etc --localstatedir=/var --sharedstatedir=/var/lib --wrap-mode=nodownload --auto-features=enabled . redhat-linux-build -Dman=true -Dhtml=true

(we've only added -Dman=true -Dhtml=true there)

[martin-belanger]

Hi @tbzatek - Thanks for mentioning the --wrap-mode= option. With that I was able to reproduce the problem you mentioned. Hopefully this latest pull request will fix the issue once and for all.

Fixed by #279

[tbzatek]

Tested git master, everything works without any issue. Thanks!