--logfile doesn't output to the specified file

[kneekoo]

Luanti version

Luanti 5.14.0 (Linux)
Using LuaJIT 2.1.1703358377
Built by GCC 13.3
Running on Linux/6.17.0 x86_64
BUILD_TYPE=Release
RUN_IN_PLACE=0
USE_CURL=1
USE_GETTEXT=1
USE_SOUND=1
STATIC_SHAREDIR="/usr/share/luanti"
STATIC_LOCALEDIR="/usr/share/locale"

Operating system and version

Linux Mint 22.3 Cinnamon

CPU model

No response

GPU model

No response

Active renderer

No response

Summary

While trying to get logging data inside a specific file, I ran Luanti like this:

luanti --verbose --logfile luanti-verbose.log

The logging stayed in the terminal, and the specified file was almost empty.

I also tried this, with the same result:
luanti --info --logfile luanti-info.log

Steps to reproduce

Run the two commands and notice how your log file won't receive all the information that you see in the terminal.

[sfan5]

--info, --verbose or --trace control the log level for printed lines. debug_log_level controls the log level for the file.

[kneekoo]

That doesn't show up with --help, but I believe that as long as --logfile is specified, the logging should go to that file. Because if it's not saved in the file, it strictly stays in the terminal and will be lost, because it doesn't go in debug.txt either.

nicu@Nicu-PC:~$ luanti --help
Allowed options:
  --address <value>           Address to connect to ('' = local game)
  --color <value>             Coloured logs ('always', 'never' or 'auto'), defaults to 'auto'
  --config <value>            Load configuration from specified file
  --console                   Start with the console open (Windows only)
  --debugger                  Try to automatically attach a debugger before starting (convenience option)
  --gameid <value>            Set gameid ("--gameid list" prints available ones)
  --go                        Skip main menu, go directly in-game
  --help                      Show allowed options
  --info                      Print more information to console
  --logfile <value>           Set log file path ('' = no logging)
  --map-dir <value>           Same as --world (deprecated)
  --migrate <value>           Migrate from current map backend to another (requires --server flag)
  --migrate-auth <value>      Migrate from current auth backend to another (requires --server flag)
  --migrate-mod-storage <value>
                              Migrate from current mod storage backend to another (requires --server flag)
  --migrate-players <value>   Migrate from current players backend to another (requires --server flag)
  --name <value>              Set player name
  --password <value>          Set password
  --password-file <value>     Set password from contents of file
  --port <value>              Set network port (UDP)
  --quiet                     Print only errors to console
  --random-input              Enable random user input (for testing)
  --recompress                Recompress the blocks of the given map database (requires --server flag)
  --run-benchmarks            Run benchmarks and exit
  --run-unittests             Run unit tests and exit
  --server                    Behave as dedicated server
  --terminal                  Enable ncurses interactive terminal (requires --server flag)
  --test-module <value>       Only run the specified test module or benchmark
  --trace                     Print enormous amounts of information to log and console
  --verbose                   Print even more information to console
  --version                   Show version information
  --world <value>             Set world path (implies local game if used with option --go)
  --worldlist <value>         Get list of worlds ('path' lists paths, 'name' lists names, 'both' lists both)
  --worldname <value>         Set world by name (implies local game if used with option --go)

Supported database backends:
  map             : dummy, leveldb, sqlite3
  players         : dummy, files, leveldb, sqlite3
  auth            : dummy, files, leveldb, sqlite3
  mod storage     : dummy, files, sqlite3

[sfan5]

I agree it can be confusing, but different log paths can have different log levels.

That doesn't show up with --help

Reading it very carefully, the options talk about "printing to console", not the log file.

[kneekoo]

debug_log_level is what I referred to as not showing up in --help. But the real problem is that anyone unaware of what the code does under the hood easily assumes that by explicitly specifying a log file, the data would go there.

Luanti doesn't mention that --info, --verbose and --trace strictly output to console, there's no mention either that those options ignore --logfile - barely anything gets logged.

What would make sense:

1. Obey --info, --verbose and --trace and output to console.
2. If --logfile is specified, use the specified log level to output everything to file.

A question remains about whether there should be output in the console when --logfile is specified. I would do both, not only because it keeps existing behavior, but it can be useful to see the output as it happens.

[sfan5]

What would you do about the existing debug_log_level setting?

[kneekoo]

As I see it, debug_log_level is supposed to be the internal default setting. The explicit use of --info, --verbose and --trace would have to override debug_log_level. Then, if --logfile is also specified, all logging should go there, since it's an explicit directive.