nixos/lib: Support derivations in escapeSystemdExecArg

They can be transformed into their outpath string, which is useful for
config generators.

1 files changed, 2 insertions, 2 deletions

diff --git a/nixos/lib/utils.nix b/nixos/lib/utils.nix
index 49ba2e5c83868..22a2c79843c66 100644
--- a/nixos/lib/utils.nix
+++ b/nixos/lib/utils.nix
@@ -64,8 +64,8 @@ rec {
     let
       s = if builtins.isPath arg then "${arg}"
         else if builtins.isString arg then arg
-        else if builtins.isInt arg || builtins.isFloat arg then toString arg
-        else throw "escapeSystemdExecArg only allows strings, paths and numbers";
+        else if builtins.isInt arg || builtins.isFloat arg || lib.isDerivation arg then toString arg
+        else throw "escapeSystemdExecArg only allows strings, paths, numbers and derivations";
     in
       replaceStrings [ "%" "$" ] [ "%%" "$$" ] (builtins.toJSON s);