pkgs.formats.yaml_1_2: init

Same as YAML 1.1 but relies on the unpinned remarshal version which emits
YAML 1.2.

pkgs/pkgs-lib/formats.nix

@@ -192,7 +192,46 @@ optionalAttrs allowAliases aliases
               (listOf valueType)
             ])
             // {
-              description = "YAML value";
+              description = "YAML 1.1 value";
+            };
+        in
+        valueType;
+
+    };
+
+  yaml_1_2 =
+    { }:
+    {
+      generate =
+        name: value:
+        pkgs.callPackage (
+          { runCommand, remarshal }:
+          runCommand name
+            {
+              nativeBuildInputs = [ remarshal ];
+              value = builtins.toJSON value;
+              passAsFile = [ "value" ];
+              preferLocalBuild = true;
+            }
+            ''
+              json2yaml "$valuePath" "$out"
+            ''
+        ) { };
+
+      type =
+        let
+          valueType =
+            nullOr (oneOf [
+              bool
+              int
+              float
+              str
+              path
+              (attrsOf valueType)
+              (listOf valueType)
+            ])
+            // {
+              description = "YAML 1.2 value";
             };
         in
         valueType;

pkgs/pkgs-lib/tests/formats.nix

@@ -143,7 +143,7 @@ runBuildTests {
   };
 
   yaml_1_1Atoms = shouldPass {
-    format = formats.yaml { };
+    format = formats.yaml_1_1 { };
     input = {
       null = null;
       false = false;
@@ -176,6 +176,40 @@ runBuildTests {
     '';
   };
 
+  yaml_1_2Atoms = shouldPass {
+    format = formats.yaml_1_2 { };
+    input = {
+      null = null;
+      false = false;
+      true = true;
+      float = 3.141;
+      str = "foo";
+      attrs.foo = null;
+      list = [
+        null
+        null
+      ];
+      path = ./testfile;
+      no = "no";
+      time = "22:30:00";
+    };
+    expected = ''
+      attrs:
+        foo: null
+      'false': false
+      float: 3.141
+      list:
+      - null
+      - null
+      no: no
+      'null': null
+      path: ${./testfile}
+      str: foo
+      time: 22:30:00
+      'true': true
+    '';
+  };
+
   iniAtoms = shouldPass {
     format = formats.ini { };
     input = {