warning: \a is an ill-defined escape sequence. In Nix, it simply means a, therefore the \ is redundant and should be removed. If the intent of the string was to mean \a instead (e.g. in a regex), you need to escape the \ itself: \\a. 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 sequence. In Nix, it simply means ', therefore the \ is redundant and should be removed. If the intent of the string was to mean \' instead (e.g. in a regex), you need to escape the \ itself: \\'. 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 sequence. In Nix, it simply means v, therefore the \ is redundant and should be removed. If the intent of the string was to mean \v instead (e.g. in a regex), you need to escape the \ itself: \\v. 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 sequence. In Nix, it simply means f, therefore the \ is redundant and should be removed. If the intent of the string was to mean \f instead (e.g. in a regex), you need to escape the \ itself: \\f. 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|