Hi Raghav,

I get a nondeterministic build failure in libdecaf:

cd /tmp/guix-build-libdecaf-1.0.drv-0/build/src/generator/curve25519 && /gnu/store/iaqmwj2290z5nnrk69bss6r0d9lpr8cs-python2-2.7.16/bin/python2.7 /tmp/guix-build-libdecaf-1.0.drv-0/source/src/generator/template.py --per=field --guard=p25519/f_field.h --item=p25519 -o /tmp/guix-build-libdecaf-1.0.drv-0/build/src/GENERATED/c/p25519/f_field.h /tmp/guix-build-libdecaf-1.0.drv-0/source/src/per_field/f_field.tmpl.h
Traceback (most recent call last):
  File "/tmp/guix-build-libdecaf-1.0.drv-0/source/src/generator/template.py", line 92, in <module>
    os.makedirs(os.path.dirname(outname))
  File "/gnu/store/iaqmwj2290z5nnrk69bss6r0d9lpr8cs-python2-2.7.16/lib/python2.7/os.py", line 157, in makedirs
    mkdir(name, mode)
OSError: [Errno 17] File exists: '/tmp/guix-build-libdecaf-1.0.drv-0/build/src/GENERATED/c/p25519'

It might not support parallel builds properly.

The next attempt did work (without changing anything).