Missing debug on calling external commands

[Eiji7]

Elixir and Erlang/OTP versions

N/A - Latest stable release, see:

$ elixir --version
Erlang/OTP 27 [erts-15.1.1] [source] [64-bit] [smp:32:32] [ds:32:32:10] [async-threads:1] [jit:ns]

Elixir 1.17.3 (compiled with Erlang/OTP 27)

Operating system

N/A - It's related to issue on Windows, but may happen on every distro/OS

Current behavior

The following line silences possible error messages coming from external commands (in related topic it's escript.exe): https://github.com/elixir-lang/elixir/blob/78f63d08313677a680868685701ae79a2459dcc1/lib/mix/lib/mix/shell.ex#L132

Here is a link to mentioned related issue posted on forum with more details from me: 26th post in Not being able to compile telemetry dependency # Phoenix Forum |> Questions / Help

Expected behavior

When status != 0 and env MIX_DEBUG is set to 1 the error message should be printed in order to further investigate issue with external commands.

[josevalim]

We do print the message as it arrives, based on the callback given. So the default shell should print those.

[josevalim]

In other words, the pass a struct to :into which calls the callback on every iteration.

[Eiji7]

Weird … for others interested here is an image from related topic:

As we can see it runs hooks and then raises Mix.Error with escript.exe command printed, but without the output …

@josevalim So you think that escript.exe have failed with exit_status > 0 and did not print any message (which was supposed to be caught and printed by default shell)?

Something like:

{"", 1} = System.shell(command, options)

[josevalim]

Yes, any message should be printed by the default callback. Perhaps there could be a bug in the System.shell command making us discard things or on escript.exe, but I think the linked code is not the one doing it. :)

[josevalim]

I will close this for now. If you have more information, please let us know and we will gladly reopen it!