Mix `cmd` in alias no longer supports globs

[kenny-evitt]

Elixir and Erlang/OTP versions

Erlang/OTP 27 [erts-15.2.2] [source] [64-bit] [smp:8:8] [ds:8:8:10] [async-threads:1] [jit]

Elixir 1.19.0-dev (ea2ae22) (compiled with Erlang/OTP 27)

Operating system

macOS 14.1.2 (23B92)

Current behavior

Example alias from mix.exs:

  defp aliases do
    [
      cp_test: [
        "cmd cp -R web/static/assets/* priv_test/static"
      ],
      ...
    ]
  end

Running the alias:

$ mix cp_test
cp: web/static/assets/*: No such file or directory
** (exit) 1
    (mix 1.19.0-dev) lib/mix/tasks/cmd.ex:82: Mix.Tasks.Cmd.run/1
    (mix 1.19.0-dev) lib/mix/task.ex:499: anonymous fn/3 in Mix.Task.run_task/5
    (mix 1.19.0-dev) lib/mix/task.ex:573: Mix.Task.run_alias/6
    (mix 1.19.0-dev) lib/mix/cli.ex:131: Mix.CLI.run_task/2
    /Users/kenny/.asdf/installs/elixir/main-otp-27/bin/mix:7: (file)

Expected behavior

In (some) previous Elixir versions, the same alias works as expected. It definitely works in 1.13.4.

The only workaround – to run cp with a glob (or at least *) – that I've found is to move the cp command to a shell script and modify the alias to run the script via a shell program, example:

  defp aliases do
    [
      cp_test: [
        "cmd bash cp_test.bash"
      ],
      ...
    ]
  end

[josevalim]

This commit changed it: #14181

We can add a flag to enable shell like behavior once again.

[pxp9]

Hello, I wanted to say that I compiled Elixir

Erlang/OTP 27 [erts-15.2.3] [source] [64-bit] [smp:12:12] [ds:12:12:10] [async-threads:1] [jit:ns]

Elixir 1.19.0-dev (ca069f7) (compiled with Erlang/OTP 27)

And did these steps and everything seems to work fine.

bin/mix new hello

cd hello

Add this in the mix.exs file.

      aliases: aliases()

  defp aliases do
    [
      copy: [
        "cmd cp -R lib/* src"
      ]
    ]
  end

Create the src folder

mkdir src

Run the alias with the expansion.

../bin/mix copy

[josevalim]

It may be a OS thing. cp in Linux may expand * while the one in macOS expects it to be expanded by the shell?

[pxp9]

hey @josevalim, I dont think this is true, I have tried cp with single quotes (prevents shell expasion) and it does not find the file.

cp '*.yml' lib

it did not expanded to all yml files, it failed because it did not find *.yml file.

@kenny-evitt , could you tell us what cp version do you have ?

I think mine is the GNU cp 9.6 .

[josevalim]

hey @josevalim, I dont think this is true, I have tried cp with single quotes (prevents shell expasion) and it does not find the file.

What about using it with the -R version?

---

@pxp9 I could reproduce it on macOS, although no way to get cps version:

STANDARDS
     The cp command is expected to be IEEE Std 1003.2 (“POSIX.2”) compatible.

HISTORY
     A cp command appeared in Version 1 AT&T UNIX.

macOS 15.3                                                                                    March 28, 2024                                                                                  

[pxp9]

Hey @josevalim,

now testing with different version of Nixos.

without quoting works as before

cp (GNU coreutils) 9.6
Packaged by https://nixos.org
Copyright (C) 2025 Free Software Foundation, Inc.
License GPLv3+: GNU GPL version 3 or later <https://gnu.org/licenses/gpl.html>.
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.

Written by Torbjörn Granlund, David MacKenzie, and Jim Meyering.

[josevalim]

@pxp9 thank you, this is very unexpected because Elixir certainly isn't expanding -R anywhere?

In any case, I was adding a --shell flag, and I just realized this could be trivially fixed by invoking the shell directly:

cp_test: "cmd sh cp -R web/static/assets/* priv_test/static"

So that's my suggestion for @kenny-evitt going forward.

[kenny-evitt]

@pxp9 I don't know how to tell what version of cp I have. The man page for cp just shows macOS 14.1 and April 17, 2022 (tho the latter might refer to when the man page itself was last updated?).

@josevalim Invoking the shell directly (in the alias command(s)) was exactly the workaround I found – I'm fine using that.

[kenny-evitt]

@josevalim @pxp9 Thanks for your help! 🙂