cli/colors: crash when importing if sys.stdout is closed

[d4l3k]

🐛 Bug

Sometimes sys.stdout is closed and isatty() throws an error at https://github.com/pytorch/torchx/blob/main/torchx/cli/colors.py#L11

Switching to a variant that checks if it's closed should work:

not sys.stdout.closed and sys.stdout.isatty()

Module (check all that applies):

• torchx.spec
• torchx.component
• torchx.apps
• torchx.runtime
• torchx.cli
• torchx.schedulers
• torchx.pipelines
• torchx.aws
• torchx.examples
• other

To Reproduce

I'm not sure how to repro this externally other than explicitly closing sys.stdout

I/O operation on closed file
Stack trace:
...
from torchx.cli.cmd_log import get_logs
File: <"/mnt/xarfuse/uid-27156/4adc7caa-seed-nspid4026533510_cgpid2017229-ns-4026533507/torchx/cli/cmd_log.py">, line 20, in <module>
from torchx.cli.colors import GREEN, ENDC
File: <"/mnt/xarfuse/uid-27156/4adc7caa-seed-nspid4026533510_cgpid2017229-ns-4026533507/torchx/cli/colors.py">, line 11, in <module>
if sys.stdout.isatty():

Expected behavior

Doesn't crash

Environment

• torchx version (e.g. 0.1.0rc1): main
• Python version:
• OS (e.g., Linux):
• How you installed torchx (conda, pip, source, docker):
• Docker image and tag (if using docker):
• Git commit (if installed from source):
• Execution environment (on-prem, AWS, GCP, Azure etc):
• Any other relevant information:

Additional context