Pinned nixpkgs is too old to build obelisk-command's closure on machines without all cores enabled

[ju1m]

Hi,

I'm not sure whether that issue should be reported here or rather to reflex-platform which seems to be where nixpkgs is pinned.

libpulseaudio is built (for ffmpeg, for openjdk, for obelisk-command),
and it fails to build on machines where not all cores are enabled
(LXC container or in my case without hyper threading on (/sys/devices/system/cpu/smt/control = off))
without this fix in recent nixpkgs

$ nix-shell # in a project using obelisk, like https://github.com/jecaro/diverk
[…]
Summary of Failures:

32/39 once-test                                                             FAIL             0.04s   exit status 1

Ok:                 38
Expected Fail:      0
Fail:               1
Unexpected Pass:    0                                               
Skipped:            0
Timeout:            0
Full log written to /build/pulseaudio-16.1/build/meson-logs/testlog.txt                                                                 
Linking dist/build/hlint/hlint ...                                  
[343/1632] Compiling C object src/shared/libsystemd-shared-251.a.p/import-util.c.o                                                      
[  0%] Building CXX object lib/Support/CMakeFiles/LLVMSupport.dir/CodeGenCoverage.cpp.o                                                 
[49/814] Compiling C object gst-libs/gst/video/libgstvideo-1.0.so.0.2003.0.p/gstvideoaffinetransformationmeta.c.o
FAILED: meson-internal__test                                        
/nix/store/n851cs4rzc49v2r41vi72q15md1h9vza-meson-0.63.1/bin/meson test --no-rebuild --print-errorlogs                                  
ninja: build stopped: subcommand failed.                            
error: builder for '/nix/store/0zi79vvizaxry4y4z6dy7z2kz079xqjm-libpulseaudio-16.1.drv' failed with exit code 1;
error: 1 dependencies of derivation '/nix/store/vg3xq3abx8hqhjyi8l5rwfglcmxnqcsy-ffmpeg-4.4.2.drv' failed to build
error: 1 dependencies of derivation '/nix/store/2wcfcbsm9h8k9666m0l1q48yv54v7lv6-openjfx-modular-sdk-17.0.0.1+1.drv' failed to build
error: 1 dependencies of derivation '/nix/store/30iyfhyrjcmma2rvjl6y23kia0k07r1b-openjdk-17.0.4+8.drv' failed to build
error: 1 dependencies of derivation '/nix/store/53wf88bj5yzjardcmxr99c1459ybrv9b-obelisk-command-0.9.0.1.drv' failed to build
error: build of '/nix/store/53wf88bj5yzjardcmxr99c1459ybrv9b-obelisk-command-0.9.0.1.drv', '/nix/store/xm76ydrgjhxff1rj8wfwb921ilqqk500-nix-prefetch-git.drv' failed

Workarounds include:

1. Using nixcache.reflex-frp.org as cache in ~/.config/nix/nix.conf:

substituers = https://nixcache.reflex-frp.org
trusted-public-keys = ryantrinkle.com-1:JJiAKaRv9mWgpVAz8dwewnZe0AzzEAzPkagE9SP5NWI=

2. Or enabling hyper threading:

$ sudo tee /sys/devices/system/cpu/smt/control <<<on

3. Or adding an overlay in nixpkgsOverlays in reflex-platform-func fixing libpulseaudio.

Alas, other build failures occur later in other packages, leaving only 1. as a viable workaround, which is quite a bad state to be in.