Wouter Deconinck a332c26780 acts: use variants['cuda_arch'] only when +cuda (#27813) ...

Since #27185, the cuda_arch variant values are conditional on +cuda. This means that for -cuda specs, the installation fails with:
```
==> acts: Executing phase: 'cmake'
==> Error: KeyError: 'cuda_arch'

/home/wdconinc/git/spack/var/spack/repos/builtin/packages/acts/package.py:222, in cmake_args:
        219        log_failure_threshold = spec.variants['log_failure_threshold'].value
        220        args.append("-DACTS_LOG_FAILURE_THRESHOLD={0}".format(log_failure_threshold))
        221
  >>    222        cuda_arch = spec.variants['cuda_arch'].value
        223        if cuda_arch != 'none':
        224            args.append('-DCUDA_FLAGS=-arch=sm_{0}'.format(cuda_arch[0]))
        225
```

2021-12-06 16:25:27 +01:00

..

spack

acts: use variants['cuda_arch'] only when +cuda (#27813)

2021-12-06 16:25:27 +01:00