diff --git a/infra/recipes/gn.expected/ci_linux.json b/infra/recipes/gn.expected/ci_linux.json
index a9265a5..81f6cb2 100644
--- a/infra/recipes/gn.expected/ci_linux.json
+++ b/infra/recipes/gn.expected/ci_linux.json
@@ -49,7 +49,7 @@
       "-root",
       "[START_DIR]/cipd",
       "-ensure-file",
-      "infra/ninja/${platform} version:1.8.2",
+      "fuchsia/clang/${platform} goma\ninfra/ninja/${platform} version:1.8.2",
       "-json-output",
       "/path/to/tmp/json"
     ],
@@ -60,6 +60,10 @@
       "@@@STEP_LOG_LINE@json.output@  \"result\": {@@@",
       "@@@STEP_LOG_LINE@json.output@    \"\": [@@@",
       "@@@STEP_LOG_LINE@json.output@      {@@@",
+      "@@@STEP_LOG_LINE@json.output@        \"instance_id\": \"resolved-instance_id-of-goma------------\", @@@",
+      "@@@STEP_LOG_LINE@json.output@        \"package\": \"fuchsia/clang/${platform}\"@@@",
+      "@@@STEP_LOG_LINE@json.output@      }, @@@",
+      "@@@STEP_LOG_LINE@json.output@      {@@@",
       "@@@STEP_LOG_LINE@json.output@        \"instance_id\": \"resolved-instance_id-of-version:1.8.2---\", @@@",
       "@@@STEP_LOG_LINE@json.output@        \"package\": \"infra/ninja/${platform}\"@@@",
       "@@@STEP_LOG_LINE@json.output@      }@@@",
@@ -80,10 +84,11 @@
       "[START_DIR]/gn/build/gen.py"
     ],
     "cwd": "[START_DIR]/gn",
-    "env_prefixes": {
-      "PATH": [
-        "[START_DIR]/cipd"
-      ]
+    "env": {
+      "AR": "[START_DIR]/cipd/bin/llvm-ar",
+      "CC": "[START_DIR]/cipd/bin/clang",
+      "CXX": "[START_DIR]/cipd/bin/clang++",
+      "LDFLAGS": "-static-libstdc++ -ldl -lpthread"
     },
     "name": "build.generate",
     "~followup_annotations": [
@@ -96,11 +101,6 @@
       "-C",
       "[START_DIR]/gn/out"
     ],
-    "env_prefixes": {
-      "PATH": [
-        "[START_DIR]/cipd"
-      ]
-    },
     "name": "build.ninja",
     "~followup_annotations": [
       "@@@STEP_NEST_LEVEL@1@@@"
diff --git a/infra/recipes/gn.expected/ci_mac.json b/infra/recipes/gn.expected/ci_mac.json
index a9265a5..7619c6f 100644
--- a/infra/recipes/gn.expected/ci_mac.json
+++ b/infra/recipes/gn.expected/ci_mac.json
@@ -80,11 +80,6 @@
       "[START_DIR]/gn/build/gen.py"
     ],
     "cwd": "[START_DIR]/gn",
-    "env_prefixes": {
-      "PATH": [
-        "[START_DIR]/cipd"
-      ]
-    },
     "name": "build.generate",
     "~followup_annotations": [
       "@@@STEP_NEST_LEVEL@1@@@"
@@ -96,11 +91,6 @@
       "-C",
       "[START_DIR]/gn/out"
     ],
-    "env_prefixes": {
-      "PATH": [
-        "[START_DIR]/cipd"
-      ]
-    },
     "name": "build.ninja",
     "~followup_annotations": [
       "@@@STEP_NEST_LEVEL@1@@@"
diff --git a/infra/recipes/gn.expected/ci_win.json b/infra/recipes/gn.expected/ci_win.json
index 0a3d7b5..b78f9ae 100644
--- a/infra/recipes/gn.expected/ci_win.json
+++ b/infra/recipes/gn.expected/ci_win.json
@@ -80,11 +80,6 @@
       "[START_DIR]\\gn\\build\\gen.py"
     ],
     "cwd": "[START_DIR]\\gn",
-    "env_prefixes": {
-      "PATH": [
-        "[START_DIR]\\cipd"
-      ]
-    },
     "name": "build.generate",
     "~followup_annotations": [
       "@@@STEP_NEST_LEVEL@1@@@"
@@ -96,11 +91,6 @@
       "-C",
       "[START_DIR]\\gn\\out"
     ],
-    "env_prefixes": {
-      "PATH": [
-        "[START_DIR]\\cipd"
-      ]
-    },
     "name": "build.ninja",
     "~followup_annotations": [
       "@@@STEP_NEST_LEVEL@1@@@"
diff --git a/infra/recipes/gn.expected/cq_linux.json b/infra/recipes/gn.expected/cq_linux.json
index e5dd9d4..4fe3e09 100644
--- a/infra/recipes/gn.expected/cq_linux.json
+++ b/infra/recipes/gn.expected/cq_linux.json
@@ -76,7 +76,7 @@
       "-root",
       "[START_DIR]/cipd",
       "-ensure-file",
-      "infra/ninja/${platform} version:1.8.2",
+      "fuchsia/clang/${platform} goma\ninfra/ninja/${platform} version:1.8.2",
       "-json-output",
       "/path/to/tmp/json"
     ],
@@ -87,6 +87,10 @@
       "@@@STEP_LOG_LINE@json.output@  \"result\": {@@@",
       "@@@STEP_LOG_LINE@json.output@    \"\": [@@@",
       "@@@STEP_LOG_LINE@json.output@      {@@@",
+      "@@@STEP_LOG_LINE@json.output@        \"instance_id\": \"resolved-instance_id-of-goma------------\", @@@",
+      "@@@STEP_LOG_LINE@json.output@        \"package\": \"fuchsia/clang/${platform}\"@@@",
+      "@@@STEP_LOG_LINE@json.output@      }, @@@",
+      "@@@STEP_LOG_LINE@json.output@      {@@@",
       "@@@STEP_LOG_LINE@json.output@        \"instance_id\": \"resolved-instance_id-of-version:1.8.2---\", @@@",
       "@@@STEP_LOG_LINE@json.output@        \"package\": \"infra/ninja/${platform}\"@@@",
       "@@@STEP_LOG_LINE@json.output@      }@@@",
@@ -107,10 +111,11 @@
       "[START_DIR]/gn/build/gen.py"
     ],
     "cwd": "[START_DIR]/gn",
-    "env_prefixes": {
-      "PATH": [
-        "[START_DIR]/cipd"
-      ]
+    "env": {
+      "AR": "[START_DIR]/cipd/bin/llvm-ar",
+      "CC": "[START_DIR]/cipd/bin/clang",
+      "CXX": "[START_DIR]/cipd/bin/clang++",
+      "LDFLAGS": "-static-libstdc++ -ldl -lpthread"
     },
     "name": "build.generate",
     "~followup_annotations": [
@@ -123,11 +128,6 @@
       "-C",
       "[START_DIR]/gn/out"
     ],
-    "env_prefixes": {
-      "PATH": [
-        "[START_DIR]/cipd"
-      ]
-    },
     "name": "build.ninja",
     "~followup_annotations": [
       "@@@STEP_NEST_LEVEL@1@@@"
diff --git a/infra/recipes/gn.expected/cq_mac.json b/infra/recipes/gn.expected/cq_mac.json
index e5dd9d4..2f59a09 100644
--- a/infra/recipes/gn.expected/cq_mac.json
+++ b/infra/recipes/gn.expected/cq_mac.json
@@ -107,11 +107,6 @@
       "[START_DIR]/gn/build/gen.py"
     ],
     "cwd": "[START_DIR]/gn",
-    "env_prefixes": {
-      "PATH": [
-        "[START_DIR]/cipd"
-      ]
-    },
     "name": "build.generate",
     "~followup_annotations": [
       "@@@STEP_NEST_LEVEL@1@@@"
@@ -123,11 +118,6 @@
       "-C",
       "[START_DIR]/gn/out"
     ],
-    "env_prefixes": {
-      "PATH": [
-        "[START_DIR]/cipd"
-      ]
-    },
     "name": "build.ninja",
     "~followup_annotations": [
       "@@@STEP_NEST_LEVEL@1@@@"
diff --git a/infra/recipes/gn.expected/cq_win.json b/infra/recipes/gn.expected/cq_win.json
index 70f96ab..d8da1a0 100644
--- a/infra/recipes/gn.expected/cq_win.json
+++ b/infra/recipes/gn.expected/cq_win.json
@@ -107,11 +107,6 @@
       "[START_DIR]\\gn\\build\\gen.py"
     ],
     "cwd": "[START_DIR]\\gn",
-    "env_prefixes": {
-      "PATH": [
-        "[START_DIR]\\cipd"
-      ]
-    },
     "name": "build.generate",
     "~followup_annotations": [
       "@@@STEP_NEST_LEVEL@1@@@"
@@ -123,11 +118,6 @@
       "-C",
       "[START_DIR]\\gn\\out"
     ],
-    "env_prefixes": {
-      "PATH": [
-        "[START_DIR]\\cipd"
-      ]
-    },
     "name": "build.ninja",
     "~followup_annotations": [
       "@@@STEP_NEST_LEVEL@1@@@"
diff --git a/infra/recipes/gn.py b/infra/recipes/gn.py
index 8268374..9c7bf33 100644
--- a/infra/recipes/gn.py
+++ b/infra/recipes/gn.py
@@ -43,17 +43,31 @@
     packages = {
         'infra/ninja/${platform}': 'version:1.8.2',
     }
+    packages.update({
+        'linux': {
+            'fuchsia/clang/${platform}': 'goma',
+        },
+        'mac': {},
+        'win': {},
+    }[api.platform.name])
     api.cipd.ensure(cipd_dir, packages)
 
-  with api.step.nest('build'):
-    with api.context(env_prefixes={'PATH': [cipd_dir]}, cwd=src_dir):
-      api.python(
-          'generate',
-          src_dir.join('build', 'gen.py'))
+  environ = {
+      'linux': {
+          'CC': cipd_dir.join('bin', 'clang'),
+          'CXX': cipd_dir.join('bin', 'clang++'),
+          'AR': cipd_dir.join('bin', 'llvm-ar'),
+          'LDFLAGS': '-static-libstdc++ -ldl -lpthread',
+      },
+      'mac': {},
+      'win': {},
+  }[api.platform.name]
 
-    with api.context(env_prefixes={'PATH': [cipd_dir]}):
-      api.step('ninja',
-              ['ninja', '-C', src_dir.join('out')])
+  with api.step.nest('build'):
+    with api.context(env=environ, cwd=src_dir):
+      api.python('generate', src_dir.join('build', 'gen.py'))
+
+    api.step('ninja', ['ninja', '-C', src_dir.join('out')])
 
   with api.context(cwd=src_dir):
     api.step('test', [src_dir.join('out', 'gn_unittests')])