Merge pull request #305752 from hercules-ci/lib-deprecated-what

lib: Document status of deprecated.nix and move it

lib/default.nix

@@ -47,7 +47,7 @@ let
     # misc
     asserts = callLibs ./asserts.nix;
     debug = callLibs ./debug.nix;
-    misc = callLibs ./deprecated.nix;
+    misc = callLibs ./deprecated/misc.nix;
 
     # domain-specific
     fetchers = callLibs ./fetchers.nix;

lib/deprecated/README.md

@@ -0,0 +1,11 @@
+
+# lib/deprecated
+
+Do not add any new functions to this directory.
+
+This directory contains the `lib.misc` sublibrary, which - as a location - is deprecated.
+Furthermore, some of the functions inside are of *dubious* utility, and should perhaps be avoided,
+while some functions *may still be needed*.
+
+This directory does not play a role in the deprecation process for library functions.
+They should be deprecated in place, by putting a `lib.warn` or `lib.warnIf` call around the function.