The desktop app's logger (StderrLog in main.rs) wrote to standard error
only. A launch from a desktop menu or the Dock has no terminal, so its
warnings were lost, and the panic log in the temp folder is gone after a
reboot: there was nothing to attach to a bug report.
apps/lightcraft/src/logging.rs replaces it (no new dependency):
- standard error plus logs/lightcraft.log in the settings folder, next
to ui.json (Linux $XDG_CONFIG_HOME/lightcraft/logs, never the library);
each launch rotates the previous log to lightcraft.1.log and .2.log, so
the log of a run that crashed survives the next start; the file is
capped at 16 MiB with one note
- records logged before the settings folder is known are buffered
(bounded) and written once the file is attached
- default levels: info for lightcraft*, warn for everything else;
LIGHTCRAFT_LOG=info|debug keeps its old meaning (a test compares it
with the old logger) and wins over RUST_LOG, which otherwise replaces
the default with env_logger-style directives
- never panics: an unusable folder or a failed write leaves standard
error as the only sink; a poisoned lock is taken back
- runs with LIGHTCRAFT_NO_PREFS (tests, scripts) log to standard error
only, so they don't rotate away the user's own logs
- a panic hook chained after the engine guard's adds escaped panics to
the file (try_lock, so a panic while logging can't hang the app);
lightcraft-panics.log in the temp folder is kept
The logger is installed first in main and the file is opened after
argument parsing (--version, --help and usage errors leave no file).
The start-up and control-server messages in main.rs and
control_server.rs go through it instead of eprintln!, and a --control
or LIGHTCRAFT_CONTROL_PORT value that isn't a port is now reported.
Documented in README (Quick start, Logs), --help and docs/whats-new.md.
Gert Pellin
47f40eb2d5