Environment Variables

These variables are available as environment variables in the commands run by melos exec and in exec scripts:

melos:
  scripts:
    echo:vars:
      exec: echo $MELOS_PACKAGE_NAME $MELOS_PACKAGE_VERSION $MELOS_PACKAGE_PATH

The variables that describe a package only exist while melos exec runs a command in that package. When you call melos exec yourself, from a terminal or from a run script, a POSIX shell expands $MELOS_PACKAGE_NAME to an empty string before Melos starts. Wrap the command in single quotes, or escape the reference as \$MELOS_PACKAGE_NAME, so that the shell started by melos exec expands it instead:

melos exec -- 'echo $MELOS_PACKAGE_NAME'

A command substitution in an exec script still runs once, before melos exec starts, so the package variables are not defined inside of it. Escape the substitution to run it in every package instead:

melos:
  scripts:
    echo:directory:
      exec: echo \$(basename $MELOS_PACKAGE_PATH)

$MELOS_PACKAGE_NAME is also replaced in the paths passed to the --file-exists package filter:

melos exec --file-exists='test_driver/$MELOS_PACKAGE_NAME_e2e.dart' -- echo hello

The path to the mono-repo root

The name of the package that's currently executing a script (when using melos exec)

The version of the package that's currently executing a script (when using melos exec)

The path of the package that's currently executing a script (when using melos exec).

The name of the parent package of the example that's currently being executed in a script (when using melos exec).

The version of the parent package of the example that's currently being executed in a script (when using melos exec).

The path of the parent package of the example that's currently being executed in a script (when using melos exec).

Whether the current publish is a dry run or not. This is true when running melos publish --dry-run and false otherwise.

If an example package exists in a directory that is a child of another package, then its parent is the 'parent package'. For example; the package firebase_auth has an example directory that is also a package, when running a melos exec script in the example package then the parent package would be firebase_auth.

Note, this 'parent package' functionality only currently works when the 'child package' name ends with example.

Define a comma delimited list of package names that Melos should focus on. This will act as the scope global package filter, and it will override the scope for all the filtering options defined in the packageFilters section.

Melos also sets this variable itself when running a script that declares packageFilters, so that a melos command invoked by the script is scoped to the selected packages.

The path to the Dart/Flutter SDK to use. This environment variable has precedence over the sdkPath option in the root pubspec.yaml, but is overridden by the command line option --sdk-path.

Set to true to only print warnings, errors and the output of failed commands. This environment variable has precedence over the quiet option in the root pubspec.yaml, but is overridden by the command line options --quiet and --no-quiet.

Melos also sets this variable itself for the scripts that it runs in quiet mode, so that a melos command invoked by a script is quiet too.

Set to true to make melos exec run the command in every package, even in the packages in which the sources did not change. This has the same effect as the command line option --run-unchanged.

Melos also sets this variable itself for the scripts that it runs with melos run --run-unchanged, so that it applies to every melos exec command invoked by a script.

Set to true to make melos exec ignore the sources of commands, so that they run in every package without calculating or storing checksums, for example on a continuous integration server. This environment variable has precedence over the ignoreSources option in the root pubspec.yaml, but is overridden by the command line options --ignore-sources and --no-ignore-sources.

Melos also sets this variable itself for the scripts that it runs with melos run --ignore-sources.

Set to true to make Melos style its output with colors, even if it does not write to a terminal, for example on a continuous integration server. Set to false to never style the output.

Melos also sets this variable itself for the scripts that it runs. Melos captures the output of those scripts, so a melos command invoked by a script cannot detect the terminal on its own and would otherwise lose its colors.

Other tools that are invoked by a script do not write to a terminal either, so most of them turn off their colors. They usually have an option to turn colors back on, for example flutter --color test or dart test --color. Scripts that need a real terminal can use stdio: inherit.