Fix bare except clauses to catch specific exceptions

[smsharma]

Critical Issue

Bare except: clauses catch ALL exceptions, including:

• KeyboardInterrupt (user pressing Ctrl+C)
• SystemExit (program exit)
• NameError, AttributeError (programming bugs)

This is dangerous because it silently masks bugs. For example, the typo mu_media_vec instead of mu_median_vec in reactions.py:147 was being silently swallowed by the bare except: at line 152 — the code appeared to work but GPU placement was silently failing.

Fix

Changed all bare except: to except (RuntimeError, IndexError): which are the specific exceptions expected when:

• RuntimeError: No GPU backend available (e.g., JAX not compiled with CUDA support)
• IndexError: GPU backend exists but no GPU devices found (empty device list)

Files Changed

File	Line	Change
linx/thermo.py	674	except: → except (RuntimeError, IndexError):
linx/weak_rates.py	105	except: → except (RuntimeError, IndexError):
linx/weak_rates.py	122	except: → except (RuntimeError, IndexError):
linx/reactions.py	152	except: → except (RuntimeError, IndexError):

Test plan

• Run existing tests: pytest pytest/
• Verify behavior on CPU-only system
• Verify behavior on GPU system

🤖 Generated with Claude Code

[cgiovanetti]

Thanks!