Repository navigation
Prometheus parser 0.22.0 raises ValueError when parsing HELP, INFO comments with double spaces #1131
Description
Issue
Starting with version 0.22.0, comment lines that are INFO, HELP will fail to parse if they contain double spaces between parts.
Example:
We have a particular service which exposes metrics in this format:
# HELP jvm_heap_size_bytes jvm heap stat
# TYPE jvm_heap_size_bytes gauge
jvm_heap_size_bytes{type="max"} 8589934592
jvm_heap_size_bytes{type="committed"} 1736441856
jvm_heap_size_bytes{type="used"} 1123733504
Expected behaviour:
Metrics of this service are successfully parsed.
list(text_fd_to_metric_families(fd)) should result with
[Metric(jvm_heap_size_bytes, jvm heap stat, gauge, , [Sample(name='jvm_heap_size_bytes', labels={'type': 'max'}, value=8589934592.0, timestamp=None, exemplar=None), Sample(name='jvm_heap_size_bytes', labels={'type': 'committed'}, value=1736441856.0, timestamp=None, exemplar=None), Sample(name='jvm_heap_size_bytes', labels={'type': 'used'}, value=1123733504.0, timestamp=None, exemplar=None)])]
(the behavior in 0.21.1)
Current behaviour:
Metrics for this service are not collected anymore since upgrading to 0.22 because of the ValueError raised during parse.
A ValueError is raised for the second and third comment lines above, as because of the double spaces, the second part becomes an empty string
Activity
csmarchbanks commentedon Sep 11, 2025
Thank you for the report, I have opened up a fix in #1134 and will cut a patch release after it is merged.
FMorgan-111 commentedon Jul 5, 2026
RepoPilot v2 could not complete an automatic fix.
Reason: Same patch produced the same failure twice.
Relevant files:
Attempts:
Attempt 1: success=False
File: unknown
Result: patch_apply_failed
Error:
Patch preflight check failed:
error: No valid patches in input (allow with "--allow-empty")
Attempt 2: success=False
File: prometheus_client/parser.py
Result: {"command": "/home/morganbest/.repopilot/repos/prometheus-client_python-work-venv/bin/python -m pytest tests/test_parser.py", "returncode": 1, "success": false}
Error:
Traceback (most recent call last):
File "", line 198, in _run_module_as_main
File "", line 88, in _run_code
File "/home/morganbest/.repopilot/repos/prometheus-client_python-work-venv/lib/python3.11/site-packages/pytest/main.py", line 9, in
raise SystemExit(_console_main())
^^^^^^^^^^^^^^^
File "/home/morganbest/.repopilot/repos/prometheus-client_python-work-venv/lib/python3.11/site-packages/_pytest/config/init.py", line 253, in _console_main
code = _main(prog=_get_prog_name(sys.argv))
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/home/morganbest/.repopilot/repos/prometheus-client_python-work-venv/lib/python3.11/site-packages/_pytest/config/init.py", line 223, in _main
config = _prepareconfig(new_args, plugins, prog=prog)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/home/morganbest/.repopilot/repos/prometheus-client_python-work-venv/lib/python3.11/site-packages/_pytest/config/init.py", line 410, in _prepareconfig
config: Config = pluginmanager.hook.pytest_cmdline_parse(
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/home/morganbest/.repopilot/repos/prometheus-client_python-work-venv/lib/python3.11/site-packages/pluggy/_hooks.py", line 512, in call
return self._hookexec(self.name, self._hookimpls.copy(), kwargs, firstresult)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/ho
Attempt 3: success=False
File: unknown
Result: patch_apply_failed
Error:
Patch preflight check failed:
error: No valid patches in input (allow with "--allow-empty")
Token usage: 20260/80000