UTF-8 characters in subprocess output make `kraft configure` crash

[TheLortex]

Describe the bug System configured for French, I tried to follow the example guide and when running kraft configure I've got:

[CRITICAL] 'ascii' codec can't decode byte 0xc2 in position 4: ordinal not in range(128)

To Reproduce Steps to reproduce the behavior:

1. Configure your system in a language that might make UTF-8 characters in program outputs
2. Run kraft configure and select a platform

Additional context

It looks like it happens here:

• https://github.com/unikraft/kraft/blob/staging/kraft/util/op.py#L67
• https://github.com/unikraft/kraft/blob/staging/kraft/util/op.py#L143

Instead the text should be decoded as UTF-8. My make command output is the following:

make : on entre dans le répertoire « /home/lucas/.unikraft/unikraft »

[antkern]

Same for me :p

Works by setting LANG=EN