find_cuda: fix crash caused by unicode chars in ldconfig output

[domschl]

find_cuda_config.py crashes, if Unicode chars are found in ldconfig output:

Traceback (most recent call last):
  File "third_party/gpus/find_cuda_config.py", line 463, in <module>
    main()
  File "third_party/gpus/find_cuda_config.py", line 455, in main
    for key, value in sorted(find_cuda_config().items()):
  File "third_party/gpus/find_cuda_config.py", line 418, in find_cuda_config
    _get_default_cuda_paths(cuda_version))
  File "third_party/gpus/find_cuda_config.py", line 159, in _get_default_cuda_paths
    ] + _get_ld_config_paths()
  File "third_party/gpus/find_cuda_config.py", line 139, in _get_ld_config_paths
    match = pattern.match(line.decode("ascii"))
UnicodeDecodeError: 'ascii' codec can't decode byte 0xc2 in position 27: ordinal not in range(128)
Asking for detailed CUDA configuration...

Localized versions of ldconfig versions use Unicode chars, e.g.: »/etc/ld.so.cache«, causing the crash.

The fix simply skips lines with Unicode chars.

[jeythekey]

This line also fixed it for me, don't know if it is a (more?) generic one:
match = pattern.match(line.decode(sys.stdin.encoding))

[domschl]

Yes, that would fix the encoding generally. So I would be happy with this too.
It could potentially unleash Unicode-filled paths on the rest of the software, if someone would use those, not sure if that would be a problem.
In most cases it seems just the first line of the output of ldconfig -p, the header-line, that causes the problem, since it is the only part that is localized and thus can contain Unicode chars:

4403 Bibliotheken im Cache »/etc/ld.so.cache« gefunden
        libzvbi.so.0 (libc6,x86-64) => /usr/lib/libzvbi.so.0
....

E.g. for German locale, the chars » and « in the header cause the issue.

[jeythekey]

Yes, that was probably also the case in my case ;) Funnily only when calling ./configure from the command line, not when executing the code in ipython or spyder.

[gbaned]

@skye can you please review this? Thanks!

[skye]

LGTM pending the one comment.