(Not sure why my previous messages weren’t signed.)

>> Now, should I test the mentioned fix?

> Yes, please do!

The coreutils package fails to build:

FAIL: test-fchownat (exit: 134)
===============================

test-chown.h:193: assertion failed

[…]

======================================
1 of 295 tests failed
(22 tests were not run)
See gnulib-tests/test-suite.log
Please report to bug-coreutils@gnu.org
======================================
make[6]: *** [test-suite.log] Error 1
make[6]: Leaving directory `/tmp/nix-build-coreutils-8.21.drv-0/coreutils-8.21/gnulib-tests'
make[5]: *** [check-TESTS] Error 2
make[5]: Leaving directory `/tmp/nix-build-coreutils-8.21.drv-0/coreutils-8.21/gnulib-tests'
make[4]: *** [check-am] Error 2
make[4]: Leaving directory `/tmp/nix-build-coreutils-8.21.drv-0/coreutils-8.21/gnulib-tests'
make[3]: *** [check-recursive] Error 1
make[3]: Leaving directory `/tmp/nix-build-coreutils-8.21.drv-0/coreutils-8.21/gnulib-tests'
make[2]: *** [check] Error 2
make[2]: Leaving directory `/tmp/nix-build-coreutils-8.21.drv-0/coreutils-8.21/gnulib-tests'
make[1]: *** [check-recursive] Error 1
make[1]: Leaving directory `/tmp/nix-build-coreutils-8.21.drv-0/coreutils-8.21'
make: *** [check] Error 2
phase `check' failed after 1756 seconds
builder for `/nix/store/09i57yii00zj9jgwlakfch928ppdkiq7-coreutils-8.21.drv' failed with exit code 1
@ build-failed /nix/store/09i57yii00zj9jgwlakfch928ppdkiq7-coreutils-8.21.drv - 1 builder for `/nix/store/09i57yii00zj9jgwlakfch928ppdkiq7-coreutils-8.21.drv' failed with exit code 1
cannot build derivation `/nix/store/a1ilh9ml81j1mm645rsp9ha7aqh3c48a-hello-2.8.drv': 1 dependencies couldn't be built
guix package: error: build failed: build of `/nix/store/a1ilh9ml81j1mm645rsp9ha7aqh3c48a-hello-2.8.drv' failed

Should I provide more information?