diff --git a/pkgs/development/compilers/vala/default.nix b/pkgs/development/compilers/vala/default.nix
index ba64e53876cb..ba9abc0def1d 100644
--- a/pkgs/development/compilers/vala/default.nix
+++ b/pkgs/development/compilers/vala/default.nix
@@ -129,13 +129,13 @@ in rec {
   };
 
   vala_0_52 = generic {
-    version = "0.52.5";
-    sha256 = "sha256-hKG7MSs+Xcrkt7JcRVmNN14stpIzzvtZoV0jUMdr3ZE=";
+    version = "0.52.6";
+    sha256 = "sha256-FNfrTZZLfDrcFuRTcTIIbdxmJO0eDruBEeKsgierOnI=";
   };
 
   vala_0_54 = generic {
-    version = "0.54.1";
-    sha256 = "0jlhd6hr9mai7hhc2c78w6zmnzf7xncp7fhyiavkqqzhhsn7gpjx";
+    version = "0.54.2";
+    sha256 = "iE3nRTF9TVbk6M7emT3I8E1Qz8o2z2DS8vJ4wwwrExE=";
   };
 
   vala = vala_0_54;
diff --git a/pkgs/development/libraries/json-glib/default.nix b/pkgs/development/libraries/json-glib/default.nix
index 9ef66fd2ce69..e041908f3f48 100644
--- a/pkgs/development/libraries/json-glib/default.nix
+++ b/pkgs/development/libraries/json-glib/default.nix
@@ -9,22 +9,20 @@
 , withIntrospection ? stdenv.buildPlatform == stdenv.hostPlatform
 , gobject-introspection
 , fixDarwinDylibNames
-, gtk-doc
-, docbook-xsl-nons
-, docbook_xml_dtd_43
+, gi-docgen
 , gnome
 }:
 
 stdenv.mkDerivation rec {
   pname = "json-glib";
-  version = "1.6.2";
+  version = "1.6.6";
 
   outputs = [ "out" "dev" ]
     ++ lib.optional withIntrospection "devdoc";
 
   src = fetchurl {
     url = "mirror://gnome/sources/${pname}/${lib.versions.majorMinor version}/${pname}-${version}.tar.xz";
-    sha256 = "092g2dyy1hhl0ix9kp33wcab0pg1qicnsv0cj5ms9g9qs336cgd3";
+    sha256 = "luyYvnqR9t3jNjZyDj2i/27LuQ52zKpJSX8xpoVaSQ4=";
   };
 
   strictDeps = true;
@@ -39,13 +37,11 @@ stdenv.mkDerivation rec {
     pkg-config
     gettext
     glib
-    docbook-xsl-nons
-    docbook_xml_dtd_43
   ] ++ lib.optional stdenv.hostPlatform.isDarwin [
     fixDarwinDylibNames
   ] ++ lib.optionals withIntrospection [
     gobject-introspection
-    gtk-doc
+    gi-docgen
   ];
 
   propagatedBuildInputs = [
@@ -54,12 +50,23 @@ stdenv.mkDerivation rec {
 
   mesonFlags = lib.optionals (!withIntrospection) [
     "-Dintrospection=disabled"
-    # doc gen uses introspection, doesn't work properly
+    # gi-docgen relies on introspection data
     "-Dgtk_doc=disabled"
   ];
 
   doCheck = true;
 
+  postFixup = ''
+    # Move developer documentation to devdoc output.
+    # Cannot be in postInstall, otherwise _multioutDocs hook in preFixup will move right back.
+    if [[ -d "$out/share/doc" ]]; then
+        find -L "$out/share/doc" -type f -regex '.*\.devhelp2?' -print0 \
+          | while IFS= read -r -d ''' file; do
+            moveToOutput "$(dirname "''${file/"$out/"/}")" "$devdoc"
+        done
+    fi
+  '';
+
   passthru = {
     updateScript = gnome.updateScript {
       packageName = pname;
diff --git a/pkgs/development/libraries/librsvg/default.nix b/pkgs/development/libraries/librsvg/default.nix
index 3abcdb1ee8c4..3d2ad81dee8a 100644
--- a/pkgs/development/libraries/librsvg/default.nix
+++ b/pkgs/development/libraries/librsvg/default.nix
@@ -24,13 +24,13 @@
 
 stdenv.mkDerivation rec {
   pname = "librsvg";
-  version = "2.52.0";
+  version = "2.52.2";
 
   outputs = [ "out" "dev" "installedTests" ];
 
   src = fetchurl {
     url = "mirror://gnome/sources/${pname}/${lib.versions.majorMinor version}/${pname}-${version}.tar.xz";
-    sha256 = "14zkdd7a9mymnfs3laqj0gr69c16nwixvbc5a4gvd534w6riz0mx";
+    sha256 = "A9KIfBj/uQbhpg+X/kanFp9pqijW210oV0jzYYsJNCc=";
   };
 
   cargoVendorDir = "vendor";
diff --git a/pkgs/development/tools/documentation/gi-docgen/default.nix b/pkgs/development/tools/documentation/gi-docgen/default.nix
index 7e8c61e1c8d2..e10fc7f8bb26 100644
--- a/pkgs/development/tools/documentation/gi-docgen/default.nix
+++ b/pkgs/development/tools/documentation/gi-docgen/default.nix
@@ -7,7 +7,7 @@
 
 python3.pkgs.buildPythonApplication rec {
   pname = "gi-docgen";
-  version = "2021.7";
+  version = "2021.8";
 
   format = "other";
 
@@ -16,7 +16,7 @@ python3.pkgs.buildPythonApplication rec {
     owner = "GNOME";
     repo = pname;
     rev = version;
-    sha256 = "i2s4JXg+D9sYq1QwVcDRLIr9qnRmzHC+cBInHv4SXHI=";
+    sha256 = "Y1IdCH6bytxbKIj48IAw/3XUQhoqwPshvdj/d1hRS3o=";
   };
 
   nativeBuildInputs = [