Return /etc/hostname when 'hostname' command does not exist

[bartlettroscoe]

In the Trilinos clang container, the command 'hostname' does not exist but the file /etc/hostname does exist.

[Copilot]

Pull request overview

Adjusts hostname detection for CI containers where the hostname executable is missing by adding a fallback mechanism.

Changes:

• Wraps hostname command execution in exception handling.
• Falls back to retrieving hostname via /etc/hostname when the command fails/returns empty.

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[Copilot]

If both the hostname command and /etc/hostname fallback fail, this now returns an empty string. That propagates into email subjects/bodies (e.g., "...: %s: %s"), producing blank hostnames and making messages harder to interpret. Consider returning a clear sentinel like "unknown" (or using socket.gethostname() as a final fallback) instead of "".

[Copilot]

Catching Exception and silently pass will also swallow unexpected failures (e.g., coding errors, KeyboardInterrupt), making debugging hard. Prefer calling getCmndOutput(..., throwOnError=False) or only catching RuntimeError from getCmndOutput and handling that explicitly (optionally with a minimal fallback value).

Suggested change

	except Exception:
	pass
	if hostname == "":
	try:
	hostname = getCmndOutput("cat /etc/hostname", True)
	except Exception:
	except RuntimeError:
	pass
	if hostname == "":
	try:
	hostname = getCmndOutput("cat /etc/hostname", True)
	except RuntimeError:

[bartlettroscoe]

@copilot open a new pull request to apply changes based on the comments in this thread

[rabartlett1972]

I tested manually in my Trilinos clang container and this passed. In that container, the hostname command does not exist.