check flags:    
[pbuilding check-recursive
Making check in logging
[pmake[1]: Entering directory `/tmp/nix-build-qfp2w1c1rki6ar2qb0a7rmc2jbmhxijl-c-library.drv-0/c-library-1.2/logging'
make[1]: Nothing to be done for `check'.
make[1]: Leaving directory `/tmp/nix-build-qfp2w1c1rki6ar2qb0a7rmc2jbmhxijl-c-library.drv-0/c-library-1.2/logging'
[qMaking check in statistics
[pmake[1]: Entering directory `/tmp/nix-build-qfp2w1c1rki6ar2qb0a7rmc2jbmhxijl-c-library.drv-0/c-library-1.2/statistics'
make[1]: Nothing to be done for `check'.
make[1]: Leaving directory `/tmp/nix-build-qfp2w1c1rki6ar2qb0a7rmc2jbmhxijl-c-library.drv-0/c-library-1.2/statistics'
[q[pmake[1]: Entering directory `/tmp/nix-build-qfp2w1c1rki6ar2qb0a7rmc2jbmhxijl-c-library.drv-0/c-library-1.2'
make[1]: Nothing to be done for `check-am'.
make[1]: Leaving directory `/tmp/nix-build-qfp2w1c1rki6ar2qb0a7rmc2jbmhxijl-c-library.drv-0/c-library-1.2'
[q[q