warning: \a is an ill-defined escape. You can drop the \ and simply write a instead. Use --extra-deprecated-features broken-string-escape to silence this warning.
         at /pwd/in.nix:1:3:
              1| "\a\n\{\$\"\'\r\v\\\t
               |   ^
              2| \f"
warning: \{ is an ill-defined escape. You can drop the \ and simply write { instead. If you meant to escape an interpolation, write \${ instead. Use --extra-deprecated-features broken-string-escape to silence this warning.
         at /pwd/in.nix:1:7:
              1| "\a\n\{\$\"\'\r\v\\\t
               |       ^
              2| \f"
warning: \' is an ill-defined escape. You can drop the \ and simply write ' instead. Use --extra-deprecated-features broken-string-escape to silence this warning.
         at /pwd/in.nix:1:13:
              1| "\a\n\{\$\"\'\r\v\\\t
               |             ^
              2| \f"
warning: \v is an ill-defined escape. You can drop the \ and simply write v instead. Use --extra-deprecated-features broken-string-escape to silence this warning.
         at /pwd/in.nix:1:17:
              1| "\a\n\{\$\"\'\r\v\\\t
               |                 ^
              2| \f"
warning: \f is an ill-defined escape. You can drop the \ and simply write f instead. Use --extra-deprecated-features broken-string-escape to silence this warning.
         at /pwd/in.nix:2:2:
              1| "\a\n\{\$\"\'\r\v\\\t
              2| \f"
               |  ^
              3|