micromamba as _conda gives Error "unknown MAMBA_EXE: filename must be mamba or micromamba"

[vroetman]

Checklist

• I added a descriptive title
• I searched open reports and couldn't find a duplicate

What happened?

When installing a constructor that was built using --conda-exe /path/to/micromamba, some packages (librsvg for example) give an error:

Linking librsvg-2.58.4-he92a37e_3
Error unknown MAMBA_EXE: "/path/to/test_error/_conda", filename must be mamba or micromamba
/path/to/test_error/install_tmp/mambafyps6ah8zte: line 3: _conda: command not found

This does not seem to affect the installation of the constructor, but I'm not sure if that is true in all situations.

These errors come from micromamba as seen here in the mamba repo and in other shell files in that folder, and the error is because it is named _conda in the constructor.

Run the following to reproduce:

# create construct.yaml
cat > construct.yaml << END
name: MicromambaError
version: 0.0.1
channels:
  - conda-forge

write_condarc: False

specs:
  - librsvg
END

# create conda environment
conda create -c conda-forge --override-channels -p ./test_env constructor=3.11.3 micromamba=2.3.1
conda activate ./test_env

# build constructor
constructor --conda-exe ./test_env/bin/micromamba  .

# install constructor
bash ./MicromambaError-0.0.1-Linux-x86_64.sh -bp test_error

Notice the errors:

Linking gdk-pixbuf-2.42.12-h7b179bb_1
Error unknown MAMBA_EXE: "/path/to/test_error/_conda", filename must be mamba or micromamba
/path/to/test_error/install_tmp/mambaf2qaaa1kt37: line 3: _conda: command not found

Linking librsvg-2.58.4-he92a37e_3
Error unknown MAMBA_EXE: "/path/to/test_error/_conda", filename must be mamba or micromamba
/path/to/test_error/install_tmp/mambafyps6ah8zte: line 3: _conda: command not found

There are also other conda packages that show this error when linking.

Additional Context

No response

[vroetman]

See also mamba-org/mamba#3575

[marcoesters]

This should be fixed by #1090. Thanks, @lrandersson!