build regression of gamescope project when building with meson >= 1.8.4

[tgurr]

Describe the bug
I hit an issue with building gamescope with meson 1.8.4 & 1.9.0 that the subprojects which got built as static .a file with meson 1.8.3 now appear to be build as dynamic .so files when using meson >= 1.8.4 and thus the resulting binary fails to run in regards to error while loading shared libraries. Initial report is at gamescope ValveSoftware/gamescope#1959.

Build log with failing meson 1.9.0 (and also 1.8.4): gamescope-3.16.17-meson-1.9.0.log resulting in runtime failure:

$ gamescope
gamescope: error while loading shared libraries: libwlroots-0.18.so: cannot open shared object file: No such file or directory

Build log with working meson 1.8.3: gamescope-3.16.17-meson-1.8.3.log resulting in working binary:

$ gamescope
[gamescope] [Info]  console: gamescope version 3.16.17
[...]

The immediate difference judging from the logs is that on latest versions (1.9.0/1.8.4) meson seems to build an .so instead of .a:
[...]x86_64-pc-linux-gnu-cc -Isubprojects/wlroots/libwlroots-0.18.so.p[...]
vs.
[...]x86_64-pc-linux-gnu-cc -Isubprojects/wlroots/libwlroots-0.18.a.p[...]

To Reproduce
Just switching meson versions is enough to reproduce, no further steps done. Working with 1.8.3 and showing different behaviour / failing once updating to 1.9.0 (or 1.8.4).

Expected behavior
Have a working endresult like with meson 1.8.3.

system parameters

• Is this a cross build or just a plain native build (for the same computer)? native
• what operating system: Exherbo Linux
• what Python version are you using: 3.12.11
• what meson --version 1.9.0/1.8.4
• what ninja --version 1.13.1

[thesamesam]

Would you mind bisecting?

[bonzini]

Likely a dup of #14940... If possible, please try the patch at #14963.

wlroots_dep = dependency(
  'wlroots',
  version: ['>= 0.18.0', '< 0.19.0'],
  fallback: ['wlroots', 'wlroots'],
  default_options: ['default_library=static', 'examples=false', 'xwayland=enabled', 'backends=libinput', 'renderers=[]', 'allocators=[]', 'session=enabled'],
)

[tgurr]

@bonzini thanks, I can confirm that applying #14963 on top of meson 1.9.0 solves the issue for me.

[eli-schwartz]

I'd like to take this opportunity to point out that Gentoo did not stabilize 1.8.* / 1.9.0. It appears exherbo has dropped all versions below 1.8.4 though...

[bonzini]

Out of curiosity, why are you using --default-library=shared?

meson setup --prefix=/usr --bindir=x86_64-pc-linux-gnu/bin --includedir=x86_64-pc-linux-gnu/include --libdir=x86_64-pc-linux-gnu/lib --libexecdir=x86_64-pc-linux-gnu/libexec --sbindir=x86_64-pc-linux-gnu/bin --auto-features=disabled --default-library=shared --native-file meson-native.txt --wrap-mode=nodownload -Davif_screenshots=enabled -Dbenchmark=enabled -Ddrm_backend=enabled -Denable_gamescope=true -Denable_gamescope_wsi_layer=true -Denable_openvr_support=false -Dinput_emulation=enabled -Drt_cap=enabled -Dsdl2_backend=enabled -Dpipewire=enabled /var/tmp/paludis/build/games-util-gamescope-3.16.17/work/gamescope-3.16.17

This is what causes the 1.8.4 change to trigger.

[tgurr]

Out of curiosity, why are you using --default-library=shared?

--default-library=shared is passed to all meson builds on our distribution by default (https://gitlab.exherbo.org/exherbo/arbor/-/blob/master/exlibs/meson.exlib#L285) to build shared libraries by default. I'm not that deep into meson but isn't this the analogy to the common autotools --enable-shared --disable-static which I guess is what most distributions use and want for multiple reasons in general to build everything possible as shared?

[bonzini]

Yes, though the libtool default is "both" and the meson default is already "shared". I suppose it helps when projects set default_library in their project() invocation, and in any case this is clearly a regression—I was just wondering.