Shebang changes how TOML tasks accept (extra) arguments?

[muzimuzhi]

For TOML tasks without shebang, extra argument are passed to the last command, as documented in https://mise.en.dev/tasks/running-tasks.html.

But for a TOML task with, for example Bash shebang, the current (mise v2026.7.13) behavior is that extra arguments are not passed to any commands, but only accessible as $1, $2, etc., just like the task's run body was saved then run as a script file.

It this the designed (though undocumented) behavior?

[tasks.multiline]
run = '''
echo "1"
echo "2 [\$1=$1]"
echo "3"
'''

[tasks.multiline-shebang]
run = '''
#!/usr/bin/env bash
echo "1"
echo "2 [\$1=$1]"
echo "3"
'''

$ mise run multiline arg ::: multiline-shebang arg
[multiline] $ echo "1" arg
[multiline] 1
[multiline] 2 [$1=]
[multiline] 3 arg
[multiline] Finished in 9.5ms
[multiline-shebang] $ echo "1" arg
[multiline-shebang] 1
[multiline-shebang] 2 [$1=arg]
[multiline-shebang] 3
[multiline-shebang] Finished in 17.9ms
Finished in 23.8ms

[jdx]

Yes, this is intentional. A shebang task is executed as a script file, so extra arguments are available through the interpreter’s normal positional-argument mechanism ($1/$@ in Bash). The “passed to the last command” documentation refers to separate entries in a run = [...] array, not lines within a multiline script.

If a task depends on particular arguments, defining them with usage is recommended. That gives the task an explicit, validated interface instead of relying on implicit passthrough behavior.

I opened #11336 to clarify this distinction in the documentation and add regression coverage.

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