diff --git a/pkgs/by-name/bu/buf/package.nix b/pkgs/by-name/bu/buf/package.nix
index 54f93cb93ed0..f90e1408fcf5 100644
--- a/pkgs/by-name/bu/buf/package.nix
+++ b/pkgs/by-name/bu/buf/package.nix
@@ -44,7 +44,7 @@ buildGoModule (finalAttrs: {
 
   preCheck = ''
     # Some tests take longer depending on builder load.
-    substituteInPlace private/bufpkg/bufcheck/lint_test.go \
+    substituteInPlace private/bufpkg/bufcheck/lint_test.go private/bufpkg/bufcheck/breaking_test.go \
       --replace-fail 'context.WithTimeout(t.Context(), 60*time.Second)' \
                      'context.WithTimeout(t.Context(), 600*time.Second)'
     # For WebAssembly runtime tests
diff --git a/pkgs/development/compilers/dart/default.nix b/pkgs/development/compilers/dart/default.nix
index c3bc2b39fd9e..033da4699ddf 100644
--- a/pkgs/development/compilers/dart/default.nix
+++ b/pkgs/development/compilers/dart/default.nix
@@ -21,11 +21,13 @@ stdenv.mkDerivation (finalAttrs: {
       system = selectSystem {
         x86_64-linux = "linux-x64";
         aarch64-linux = "linux-arm64";
+        riscv64-linux = "linux-riscv64";
         aarch64-darwin = "macos-arm64";
       };
       hash = selectSystem {
         x86_64-linux = "sha256-h5Alc/rNisrKx+4f5z+o0GaOBgZQFgaOLtbFyZxrHuA=";
         aarch64-linux = "sha256-IBQaBlMyeTm7IMS4eyMSJr66ESjYqa7bswy1rxonkNQ=";
+        riscv64-linux = "sha256-VmvqaHCVsXv9W8+YdgnWAaW+THuDcc851O/6czx7WFE=";
         aarch64-darwin = "sha256-GBLWAq7Qqc9ygck/UUoeGuz2DcNFxDN9uk/yj6jTmMo=";
       };
     in
@@ -112,6 +114,7 @@ stdenv.mkDerivation (finalAttrs: {
       "x86_64-linux"
       "aarch64-linux"
       "aarch64-darwin"
+      "riscv64-linux"
     ];
     sourceProvenance = with lib.sourceTypes; [ binaryNativeCode ];
     license = lib.licenses.bsd3;
diff --git a/pkgs/top-level/all-packages.nix b/pkgs/top-level/all-packages.nix
index c513367022e9..5e7726cb782c 100644
--- a/pkgs/top-level/all-packages.nix
+++ b/pkgs/top-level/all-packages.nix
@@ -10757,7 +10757,7 @@ with pkgs;
     dart-source
     ;
 
-  dart = if stdenv.hostPlatform.isLinux then dart-source else dart-bin;
+  dart = if lib.meta.availableOn stdenv.hostPlatform dart-source then dart-source else dart-bin;
 
   pub2nix = recurseIntoAttrs (callPackage ../build-support/dart/pub2nix { });