rebar3 version compiles dependencies before outputting value

[paulo-ferraz-oliveira]

Pre-Check

• I found no current issues for this (quick search)
• I'm willing and interested in helping fix the issue

Environment

• rebar3 3.22.1

Current behaviour

My use case is as follows:

• I want to use erlef/setup-beam's version-file (e.g. .tool-versions) build option
• for that I need to use actions/checkout before I use erlef/setup-beam (because my .tool-versions is checked in to my project - for CI/local sync. purposes)
• when I do use erlef/setup-beam the action attempts to output the chosen rebar3 version, for debugging purposes, via rebar3 version
• this forces a compilation of my project that will e.g. fail in a step it shouldn't (because I wasn't expecting it to be compiled for this reason: rebar3 version)

My question is: is it absolutely necessary that rebar3 version attempts compilation?

Expected behaviour

No compilation should be required for rebar3 version.

[ferd]

rebar3 version has no command dependencies and does not require compiling before outputting a version.

An exception can be made for this specifically for global plugins if they are defined in a global configuration file, because a global project plugin could override the version command and must therefore be evaluated before any command is run. To avoid that, calling it with a path such as REBAR_GLOBAL_CONFIG_DIR=/fake-dir rebar3 version will necessarily bypass any such checks and output faster.

[ferd]

Now that I think about it, calling rebar3 version from within a project that defines plugins will also have the same effect. REBAR_GLOBAL_CONFIG_DIR=/fake-dir REBAR_CONFIG=fake.config rebar3 version should cancel out all config file reading if you can't call the version from a neutral location.

[paulo-ferraz-oliveira]

Oh, cool. I can live with REBAR_GLOBAL_CONFIG_DIR=/fake-dir REBAR_CONFIG=fake.config. My use case is basically setup-beam which affects many consumers. Thanks, @ferd.

[ferd]

If I recall correctly you can also grab the version from the top of the escript, but it won't be as complete:

$ head -2 rebar3 | tail -1
%% Rebar3 3.22.1

The full version gives specific hashes with the OTP version and is more useful.

[paulo-ferraz-oliveira]

Cool, thanks. At the moment I'm running it, though, making sure it's executable, and in the path, is also part of the test 😄