[rquirk]

There's just one scenario: a completely absent #! line.

It's an easy fix, just add the line, otherwise 0755 scripts with no #! do execute using the current shell.

[eridius]

That doesn't work for me (in Fish).

  > cat foo
  echo wat
  > ./foo
  Failed to execute process './foo'. Reason:
  exec: Exec format error
  The file './foo' is marked as an executable but could not be run by the operating system.

It does however work in Bash. So this appears to be a bash-ism, rather than an OS feature.

[rquirk]

Ah, bummer. I tested in csh too but not fish.