nix-shell in second #! line only accepts double quotes for package expressions

[cumber]

This works:

#! /usr/bin/env nix-shell
#! nix-shell -i runghc -p "ghc.withPackages (ps: [ ps.HTTP ])"

This does not:

#! /usr/bin/env nix-shell
#! nix-shell -i runghc -p 'ghc.withPackages (ps: [ ps.HTTP ])'

Running a script with the above lines produces: error: syntax error, unexpected $undefined, at (string):1:94

The syntax of the extra #! nix-shell lines looks like we're writing shell command syntax, so people think that bash-like (or at least sh-like) quoting rules would apply.

Ideally single quotes would work as well as double quotes, but either way the manual (https://nixos.org/nix/manual/#ssec-nix-shell-shebang) should at talk about how to properly quote complex arguments; currently none of the examples need quoting, and there is no mention of whether any kind of quoting is supported or not (which leads to the guess that bash-like quotes would be supported from the similar syntax).

[bhipple]

This actually just bit me a few days ago while trying to use a python.withPackages. I eventually figured out the right syntax is as you have written above but a quick mention in the manual or a complex example would've been nice!

[toonn]

This is a regression. I got the exact same error on a haskell script I've used succesfully before.

[domenkozar]

Needs single quote handling in

nix/src/nix-build/nix-build.cc

Line 53 in a0ef212

case '"':

[AleXoundOS]

Not only package expression is affected, but any expression in single quotes. The problem is that inner double quotes need to be escaped:

#! /usr/bin/env nix-shell
#! nix-shell -E "with import <nixpkgs> {}; runCommand \"dummy\" {} \"\""

[stale]

I marked this as stale due to inactivity. → More info

[AleXoundOS]

For those, who needs long/complex nix expression in shebang in a single file, I've found a semi-solution with the help of /usr/bin/env -S, what avoids this quotes issue as well.

[stale]

I marked this as stale due to inactivity. → More info

[ncfavier]

#8470