Update GN recipes for Windows.

fetch-gn is a Python script, gn is a batch script, and ninja is an exe.

Pass the win_toolchain package to GN as windk.  This won't work yet.

GOLD_TRYBOT_URL= https://gold.skia.org/search?issue=3245

Change-Id: Iacc59c70c06ec118fc6a45d0cdb67095ff2b951b
Reviewed-on: https://skia-review.googlesource.com/3245
Reviewed-by: Mike Klein <mtklein@chromium.org>
Commit-Queue: Mike Klein <mtklein@chromium.org>

27 files changed, 73 insertions, 9 deletions

diff --git a/infra/bots/recipe_modules/flavor/gn_flavor.py b/infra/bots/recipe_modules/flavor/gn_flavor.py
index a4d5fca05d..5742319764 100644
--- a/infra/bots/recipe_modules/flavor/gn_flavor.py
+++ b/infra/bots/recipe_modules/flavor/gn_flavor.py
@@ -24,13 +24,21 @@ class GNFlavorUtils(default_flavor.DefaultFlavorUtils):
       os == 'Ubuntu' and target_arch == 'x86',
     ])
 
-  def _run(self, title, cmd, env=None, infra_step=False):
+  def _strip_environment(self):
     self.m.vars.default_env = {k: v for (k,v)
                                in self.m.vars.default_env.iteritems()
                                if k in ['PATH']}
+
+  def _run(self, title, cmd, env=None, infra_step=False):
+    self._strip_environment()
     self.m.run(self.m.step, title, cmd=cmd,
                env=env, cwd=self.m.vars.skia_dir, infra_step=infra_step)
 
+  def _py(self, title, script, env=None, infra_step=True):
+    self._strip_environment()
+    self.m.run(self.m.python, title, script=script,
+               env=env, cwd=self.m.vars.skia_dir, infra_step=infra_step)
+
   def build_command_buffer(self):
     self.m.run(self.m.python, 'build command_buffer',
         script=self.m.vars.skia_dir.join('tools', 'build_command_buffer.py'),
@@ -48,7 +56,8 @@ class GNFlavorUtils(default_flavor.DefaultFlavorUtils):
     os            = self.m.vars.builder_cfg.get('os',            '')
     target_arch   = self.m.vars.builder_cfg.get('target_arch',   '')
 
-    clang_linux = str(self.m.vars.slave_dir.join('clang_linux'))
+    clang_linux   = str(self.m.vars.slave_dir.join('clang_linux'))
+    win_toolchain = str(self.m.vars.slave_dir.join('t'))
 
     cc, cxx = None, None
     extra_cflags = []
@@ -91,6 +100,7 @@ class GNFlavorUtils(default_flavor.DefaultFlavorUtils):
       'cxx': cxx,
       'sanitize': extra_config if 'SAN' in extra_config else '',
       'target_cpu': 'x86' if target_arch == 'x86' else '',
+      'windk': win_toolchain if 'Win' in os else '',
     }.iteritems():
       if v:
         args[k] = '"%s"' % v
@@ -101,10 +111,12 @@ class GNFlavorUtils(default_flavor.DefaultFlavorUtils):
 
     gn_args = ' '.join('%s=%s' % (k,v) for (k,v) in sorted(args.iteritems()))
 
-    self._run('fetch-gn', [self.m.vars.skia_dir.join('bin', 'fetch-gn')],
-              infra_step=True)
-    self._run('gn gen', ['gn', 'gen', self.out_dir, '--args=' + gn_args])
-    self._run('ninja', ['ninja', '-C', self.out_dir])
+    gn    = 'gn.bat'    if 'Win' in os else 'gn'
+    ninja = 'ninja.exe' if 'Win' in os else 'ninja'
+
+    self._py('fetch-gn', self.m.vars.skia_dir.join('bin', 'fetch-gn'))
+    self._run('gn gen', [gn, 'gen', self.out_dir, '--args=' + gn_args])
+    self._run('ninja', [ninja, '-C', self.out_dir])
 
   def step(self, name, cmd, env=None, **kwargs):
     app = self.m.vars.skia_out.join(self.m.vars.configuration, cmd[0])
diff --git a/infra/bots/recipes/swarm_compile.expected/Build-Mac-Clang-x86_64-Debug-CommandBuffer.json b/infra/bots/recipes/swarm_compile.expected/Build-Mac-Clang-x86_64-Debug-CommandBuffer.json
index 6fa0d25a68..296bc17a28 100644
--- a/infra/bots/recipes/swarm_compile.expected/Build-Mac-Clang-x86_64-Debug-CommandBuffer.json
+++ b/infra/bots/recipes/swarm_compile.expected/Build-Mac-Clang-x86_64-Debug-CommandBuffer.json
@@ -162,6 +162,8 @@
   },
   {
     "cmd": [
+      "python",
+      "-u",
       "[CUSTOM_/_B_WORK]/skia/bin/fetch-gn"
     ],
     "cwd": "[CUSTOM_/_B_WORK]/skia",
diff --git a/infra/bots/recipes/swarm_compile.expected/Build-Mac-Clang-x86_64-Release-GN.json b/infra/bots/recipes/swarm_compile.expected/Build-Mac-Clang-x86_64-Release-GN.json
index 4f2a133c99..afb2ad8b5d 100644
--- a/infra/bots/recipes/swarm_compile.expected/Build-Mac-Clang-x86_64-Release-GN.json
+++ b/infra/bots/recipes/swarm_compile.expected/Build-Mac-Clang-x86_64-Release-GN.json
@@ -121,6 +121,8 @@
   },
   {
     "cmd": [
+      "python",
+      "-u",
       "[CUSTOM_/_B_WORK]/skia/bin/fetch-gn"
     ],
     "cwd": "[CUSTOM_/_B_WORK]/skia",
diff --git a/infra/bots/recipes/swarm_compile.expected/Build-Ubuntu-Clang-x86_64-Debug-ASAN.json b/infra/bots/recipes/swarm_compile.expected/Build-Ubuntu-Clang-x86_64-Debug-ASAN.json
index 8d0c0cbd7c..2736afd54d 100644
--- a/infra/bots/recipes/swarm_compile.expected/Build-Ubuntu-Clang-x86_64-Debug-ASAN.json
+++ b/infra/bots/recipes/swarm_compile.expected/Build-Ubuntu-Clang-x86_64-Debug-ASAN.json
@@ -121,6 +121,8 @@
   },
   {
     "cmd": [
+      "python",
+      "-u",
       "[CUSTOM_/_B_WORK]/skia/bin/fetch-gn"
     ],
     "cwd": "[CUSTOM_/_B_WORK]/skia",
diff --git a/infra/bots/recipes/swarm_compile.expected/Build-Ubuntu-Clang-x86_64-Debug-GN.json b/infra/bots/recipes/swarm_compile.expected/Build-Ubuntu-Clang-x86_64-Debug-GN.json
index f3a6c826f0..63a6c02458 100644
--- a/infra/bots/recipes/swarm_compile.expected/Build-Ubuntu-Clang-x86_64-Debug-GN.json
+++ b/infra/bots/recipes/swarm_compile.expected/Build-Ubuntu-Clang-x86_64-Debug-GN.json
@@ -121,6 +121,8 @@
   },
   {
     "cmd": [
+      "python",
+      "-u",
       "[CUSTOM_/_B_WORK]/skia/bin/fetch-gn"
     ],
     "cwd": "[CUSTOM_/_B_WORK]/skia",
diff --git a/infra/bots/recipes/swarm_compile.expected/Build-Ubuntu-GCC-x86-Debug.json b/infra/bots/recipes/swarm_compile.expected/Build-Ubuntu-GCC-x86-Debug.json
index 3555d1ad1e..c184198290 100644
--- a/infra/bots/recipes/swarm_compile.expected/Build-Ubuntu-GCC-x86-Debug.json
+++ b/infra/bots/recipes/swarm_compile.expected/Build-Ubuntu-GCC-x86-Debug.json
@@ -121,6 +121,8 @@
   },
   {
     "cmd": [
+      "python",
+      "-u",
       "[CUSTOM_/_B_WORK]/skia/bin/fetch-gn"
     ],
     "cwd": "[CUSTOM_/_B_WORK]/skia",
diff --git a/infra/bots/recipes/swarm_compile.expected/Build-Ubuntu-GCC-x86_64-Debug-GN.json b/infra/bots/recipes/swarm_compile.expected/Build-Ubuntu-GCC-x86_64-Debug-GN.json
index 33659c3736..b92a4ea481 100644
--- a/infra/bots/recipes/swarm_compile.expected/Build-Ubuntu-GCC-x86_64-Debug-GN.json
+++ b/infra/bots/recipes/swarm_compile.expected/Build-Ubuntu-GCC-x86_64-Debug-GN.json
@@ -121,6 +121,8 @@
   },
   {
     "cmd": [
+      "python",
+      "-u",
       "[CUSTOM_/_B_WORK]/skia/bin/fetch-gn"
     ],
     "cwd": "[CUSTOM_/_B_WORK]/skia",
diff --git a/infra/bots/recipes/swarm_compile.expected/Build-Ubuntu-GCC-x86_64-Debug-MSAN.json b/infra/bots/recipes/swarm_compile.expected/Build-Ubuntu-GCC-x86_64-Debug-MSAN.json
index febfd4390f..eb857e3e16 100644
--- a/infra/bots/recipes/swarm_compile.expected/Build-Ubuntu-GCC-x86_64-Debug-MSAN.json
+++ b/infra/bots/recipes/swarm_compile.expected/Build-Ubuntu-GCC-x86_64-Debug-MSAN.json
@@ -121,6 +121,8 @@
   },
   {
     "cmd": [
+      "python",
+      "-u",
       "[CUSTOM_/_B_WORK]/skia/bin/fetch-gn"
     ],
     "cwd": "[CUSTOM_/_B_WORK]/skia",
diff --git a/infra/bots/recipes/swarm_compile.expected/Build-Ubuntu-GCC-x86_64-Debug-NoGPU.json b/infra/bots/recipes/swarm_compile.expected/Build-Ubuntu-GCC-x86_64-Debug-NoGPU.json
index a463745267..9d20fd3055 100644
--- a/infra/bots/recipes/swarm_compile.expected/Build-Ubuntu-GCC-x86_64-Debug-NoGPU.json
+++ b/infra/bots/recipes/swarm_compile.expected/Build-Ubuntu-GCC-x86_64-Debug-NoGPU.json
@@ -121,6 +121,8 @@
   },
   {
     "cmd": [
+      "python",
+      "-u",
       "[CUSTOM_/_B_WORK]/skia/bin/fetch-gn"
     ],
     "cwd": "[CUSTOM_/_B_WORK]/skia",
diff --git a/infra/bots/recipes/swarm_compile.expected/Build-Ubuntu-GCC-x86_64-Debug-SK_USE_DISCARDABLE_SCALEDIMAGECACHE.json b/infra/bots/recipes/swarm_compile.expected/Build-Ubuntu-GCC-x86_64-Debug-SK_USE_DISCARDABLE_SCALEDIMAGECACHE.json
index b668f31e93..54c6712ca3 100644
--- a/infra/bots/recipes/swarm_compile.expected/Build-Ubuntu-GCC-x86_64-Debug-SK_USE_DISCARDABLE_SCALEDIMAGECACHE.json
+++ b/infra/bots/recipes/swarm_compile.expected/Build-Ubuntu-GCC-x86_64-Debug-SK_USE_DISCARDABLE_SCALEDIMAGECACHE.json
@@ -121,6 +121,8 @@
   },
   {
     "cmd": [
+      "python",
+      "-u",
       "[CUSTOM_/_B_WORK]/skia/bin/fetch-gn"
     ],
     "cwd": "[CUSTOM_/_B_WORK]/skia",
diff --git a/infra/bots/recipes/swarm_compile.expected/Build-Ubuntu-GCC-x86_64-Release-ANGLE.json b/infra/bots/recipes/swarm_compile.expected/Build-Ubuntu-GCC-x86_64-Release-ANGLE.json
index 05ea9e4ae4..e9e752acc5 100644
--- a/infra/bots/recipes/swarm_compile.expected/Build-Ubuntu-GCC-x86_64-Release-ANGLE.json
+++ b/infra/bots/recipes/swarm_compile.expected/Build-Ubuntu-GCC-x86_64-Release-ANGLE.json
@@ -121,6 +121,8 @@
   },
   {
     "cmd": [
+      "python",
+      "-u",
       "[CUSTOM_/_B_WORK]/skia/bin/fetch-gn"
     ],
     "cwd": "[CUSTOM_/_B_WORK]/skia",
diff --git a/infra/bots/recipes/swarm_compile.expected/Build-Ubuntu-GCC-x86_64-Release-Fast.json b/infra/bots/recipes/swarm_compile.expected/Build-Ubuntu-GCC-x86_64-Release-Fast.json
index 5b57b34bd1..3dbcf3028b 100644
--- a/infra/bots/recipes/swarm_compile.expected/Build-Ubuntu-GCC-x86_64-Release-Fast.json
+++ b/infra/bots/recipes/swarm_compile.expected/Build-Ubuntu-GCC-x86_64-Release-Fast.json
@@ -121,6 +121,8 @@
   },
   {
     "cmd": [
+      "python",
+      "-u",
       "[CUSTOM_/_B_WORK]/skia/bin/fetch-gn"
     ],
     "cwd": "[CUSTOM_/_B_WORK]/skia",
diff --git a/infra/bots/recipes/swarm_compile.expected/Build-Ubuntu-GCC-x86_64-Release-Mesa.json b/infra/bots/recipes/swarm_compile.expected/Build-Ubuntu-GCC-x86_64-Release-Mesa.json
index 59fe37fec0..f3f5490bdc 100644
--- a/infra/bots/recipes/swarm_compile.expected/Build-Ubuntu-GCC-x86_64-Release-Mesa.json
+++ b/infra/bots/recipes/swarm_compile.expected/Build-Ubuntu-GCC-x86_64-Release-Mesa.json
@@ -121,6 +121,8 @@
   },
   {
     "cmd": [
+      "python",
+      "-u",
       "[CUSTOM_/_B_WORK]/skia/bin/fetch-gn"
     ],
     "cwd": "[CUSTOM_/_B_WORK]/skia",
diff --git a/infra/bots/recipes/swarm_compile.expected/Build-Ubuntu-GCC-x86_64-Release-Valgrind.json b/infra/bots/recipes/swarm_compile.expected/Build-Ubuntu-GCC-x86_64-Release-Valgrind.json
index c3f9260744..f7234aebe7 100644
--- a/infra/bots/recipes/swarm_compile.expected/Build-Ubuntu-GCC-x86_64-Release-Valgrind.json
+++ b/infra/bots/recipes/swarm_compile.expected/Build-Ubuntu-GCC-x86_64-Release-Valgrind.json
@@ -121,6 +121,8 @@
   },
   {
     "cmd": [
+      "python",
+      "-u",
       "[CUSTOM_/_B_WORK]/skia/bin/fetch-gn"
     ],
     "cwd": "[CUSTOM_/_B_WORK]/skia",
diff --git a/infra/bots/recipes/swarm_compile.expected/Build-Win-MSVC-x86-Release-GN.json b/infra/bots/recipes/swarm_compile.expected/Build-Win-MSVC-x86-Release-GN.json
index ce0290855e..49a9c7a749 100644
--- a/infra/bots/recipes/swarm_compile.expected/Build-Win-MSVC-x86-Release-GN.json
+++ b/infra/bots/recipes/swarm_compile.expected/Build-Win-MSVC-x86-Release-GN.json
@@ -121,6 +121,8 @@
   },
   {
     "cmd": [
+      "python",
+      "-u",
       "[CUSTOM_C:\\_B_WORK]\\skia\\bin\\fetch-gn"
     ],
     "cwd": "[CUSTOM_C:\\_B_WORK]\\skia",
@@ -131,10 +133,10 @@
   },
   {
     "cmd": [
-      "gn",
+      "gn.bat",
       "gen",
       "[CUSTOM_C:\\_B_WORK]\\skia\\out\\Build-Win-MSVC-x86-Release-GN\\Release",
-      "--args=is_debug=false target_cpu=\"x86\""
+      "--args=is_debug=false target_cpu=\"x86\" windk=\"[SLAVE_BUILD]\\t\""
     ],
     "cwd": "[CUSTOM_C:\\_B_WORK]\\skia",
     "env": {
@@ -144,7 +146,7 @@
   },
   {
     "cmd": [
-      "ninja",
+      "ninja.exe",
       "-C",
       "[CUSTOM_C:\\_B_WORK]\\skia\\out\\Build-Win-MSVC-x86-Release-GN\\Release"
     ],
diff --git a/infra/bots/recipes/swarm_ct_skps.expected/CT_CPU_BENCH_10k_SKPs.json b/infra/bots/recipes/swarm_ct_skps.expected/CT_CPU_BENCH_10k_SKPs.json
index 88b7dedd6a..e968bd6fa8 100644
--- a/infra/bots/recipes/swarm_ct_skps.expected/CT_CPU_BENCH_10k_SKPs.json
+++ b/infra/bots/recipes/swarm_ct_skps.expected/CT_CPU_BENCH_10k_SKPs.json
@@ -143,6 +143,8 @@
   },
   {
     "cmd": [
+      "python",
+      "-u",
       "[CUSTOM_/_B_WORK]/skia/bin/fetch-gn"
     ],
     "cwd": "[CUSTOM_/_B_WORK]/skia",
diff --git a/infra/bots/recipes/swarm_ct_skps.expected/CT_DM_100k_SKPs.json b/infra/bots/recipes/swarm_ct_skps.expected/CT_DM_100k_SKPs.json
index 1fac56ce75..b85ec8d9fa 100644
--- a/infra/bots/recipes/swarm_ct_skps.expected/CT_DM_100k_SKPs.json
+++ b/infra/bots/recipes/swarm_ct_skps.expected/CT_DM_100k_SKPs.json
@@ -143,6 +143,8 @@
   },
   {
     "cmd": [
+      "python",
+      "-u",
       "[CUSTOM_/_B_WORK]/skia/bin/fetch-gn"
     ],
     "cwd": "[CUSTOM_/_B_WORK]/skia",
diff --git a/infra/bots/recipes/swarm_ct_skps.expected/CT_DM_10k_SKPs.json b/infra/bots/recipes/swarm_ct_skps.expected/CT_DM_10k_SKPs.json
index 9a13c4ee76..fbd9fed51d 100644
--- a/infra/bots/recipes/swarm_ct_skps.expected/CT_DM_10k_SKPs.json
+++ b/infra/bots/recipes/swarm_ct_skps.expected/CT_DM_10k_SKPs.json
@@ -143,6 +143,8 @@
   },
   {
     "cmd": [
+      "python",
+      "-u",
       "[CUSTOM_/_B_WORK]/skia/bin/fetch-gn"
     ],
     "cwd": "[CUSTOM_/_B_WORK]/skia",
diff --git a/infra/bots/recipes/swarm_ct_skps.expected/CT_DM_10k_SKPs_Trybot.json b/infra/bots/recipes/swarm_ct_skps.expected/CT_DM_10k_SKPs_Trybot.json
index 5960092d2f..2162a92207 100644
--- a/infra/bots/recipes/swarm_ct_skps.expected/CT_DM_10k_SKPs_Trybot.json
+++ b/infra/bots/recipes/swarm_ct_skps.expected/CT_DM_10k_SKPs_Trybot.json
@@ -163,6 +163,8 @@
   },
   {
     "cmd": [
+      "python",
+      "-u",
       "[CUSTOM_/_B_WORK]/skia/bin/fetch-gn"
     ],
     "cwd": "[CUSTOM_/_B_WORK]/skia",
diff --git a/infra/bots/recipes/swarm_ct_skps.expected/CT_DM_1m_SKPs.json b/infra/bots/recipes/swarm_ct_skps.expected/CT_DM_1m_SKPs.json
index 04fb4e5297..3fe84e2109 100644
--- a/infra/bots/recipes/swarm_ct_skps.expected/CT_DM_1m_SKPs.json
+++ b/infra/bots/recipes/swarm_ct_skps.expected/CT_DM_1m_SKPs.json
@@ -143,6 +143,8 @@
   },
   {
     "cmd": [
+      "python",
+      "-u",
       "[CUSTOM_/_B_WORK]/skia/bin/fetch-gn"
     ],
     "cwd": "[CUSTOM_/_B_WORK]/skia",
diff --git a/infra/bots/recipes/swarm_ct_skps.expected/CT_DM_1m_SKPs_2slaves_failure.json b/infra/bots/recipes/swarm_ct_skps.expected/CT_DM_1m_SKPs_2slaves_failure.json
index 8d747f6a95..79fbe6536d 100644
--- a/infra/bots/recipes/swarm_ct_skps.expected/CT_DM_1m_SKPs_2slaves_failure.json
+++ b/infra/bots/recipes/swarm_ct_skps.expected/CT_DM_1m_SKPs_2slaves_failure.json
@@ -143,6 +143,8 @@
   },
   {
     "cmd": [
+      "python",
+      "-u",
       "[CUSTOM_/_B_WORK]/skia/bin/fetch-gn"
     ],
     "cwd": "[CUSTOM_/_B_WORK]/skia",
diff --git a/infra/bots/recipes/swarm_ct_skps.expected/CT_DM_1m_SKPs_slave3_failure.json b/infra/bots/recipes/swarm_ct_skps.expected/CT_DM_1m_SKPs_slave3_failure.json
index 470d3c4fff..69d65b211a 100644
--- a/infra/bots/recipes/swarm_ct_skps.expected/CT_DM_1m_SKPs_slave3_failure.json
+++ b/infra/bots/recipes/swarm_ct_skps.expected/CT_DM_1m_SKPs_slave3_failure.json
@@ -143,6 +143,8 @@
   },
   {
     "cmd": [
+      "python",
+      "-u",
       "[CUSTOM_/_B_WORK]/skia/bin/fetch-gn"
     ],
     "cwd": "[CUSTOM_/_B_WORK]/skia",
diff --git a/infra/bots/recipes/swarm_ct_skps.expected/CT_GPU_BENCH_10k_SKPs.json b/infra/bots/recipes/swarm_ct_skps.expected/CT_GPU_BENCH_10k_SKPs.json
index 6964598542..76224f18e2 100644
--- a/infra/bots/recipes/swarm_ct_skps.expected/CT_GPU_BENCH_10k_SKPs.json
+++ b/infra/bots/recipes/swarm_ct_skps.expected/CT_GPU_BENCH_10k_SKPs.json
@@ -143,6 +143,8 @@
   },
   {
     "cmd": [
+      "python",
+      "-u",
       "[CUSTOM_/_B_WORK]/skia/bin/fetch-gn"
     ],
     "cwd": "[CUSTOM_/_B_WORK]/skia",
diff --git a/infra/bots/recipes/swarm_ct_skps.expected/CT_GPU_BENCH_1k_SKPs.json b/infra/bots/recipes/swarm_ct_skps.expected/CT_GPU_BENCH_1k_SKPs.json
index 0372f6998e..b3fbcc4909 100644
--- a/infra/bots/recipes/swarm_ct_skps.expected/CT_GPU_BENCH_1k_SKPs.json
+++ b/infra/bots/recipes/swarm_ct_skps.expected/CT_GPU_BENCH_1k_SKPs.json
@@ -143,6 +143,8 @@
   },
   {
     "cmd": [
+      "python",
+      "-u",
       "[CUSTOM_/_B_WORK]/skia/bin/fetch-gn"
     ],
     "cwd": "[CUSTOM_/_B_WORK]/skia",
diff --git a/infra/bots/recipes/swarm_ct_skps.expected/CT_IMG_DECODE_100k_SKPs.json b/infra/bots/recipes/swarm_ct_skps.expected/CT_IMG_DECODE_100k_SKPs.json
index 413cd2c555..d2cc054ca9 100644
--- a/infra/bots/recipes/swarm_ct_skps.expected/CT_IMG_DECODE_100k_SKPs.json
+++ b/infra/bots/recipes/swarm_ct_skps.expected/CT_IMG_DECODE_100k_SKPs.json
@@ -143,6 +143,8 @@
   },
   {
     "cmd": [
+      "python",
+      "-u",
       "[CUSTOM_/_B_WORK]/skia/bin/fetch-gn"
     ],
     "cwd": "[CUSTOM_/_B_WORK]/skia",
diff --git a/infra/bots/recipes/swarm_ct_skps.expected/CT_IMG_DECODE_10k_SKPs.json b/infra/bots/recipes/swarm_ct_skps.expected/CT_IMG_DECODE_10k_SKPs.json
index 551baa05da..15c52aa080 100644
--- a/infra/bots/recipes/swarm_ct_skps.expected/CT_IMG_DECODE_10k_SKPs.json
+++ b/infra/bots/recipes/swarm_ct_skps.expected/CT_IMG_DECODE_10k_SKPs.json
@@ -143,6 +143,8 @@
   },
   {
     "cmd": [
+      "python",
+      "-u",
       "[CUSTOM_/_B_WORK]/skia/bin/fetch-gn"
     ],
     "cwd": "[CUSTOM_/_B_WORK]/skia",
diff --git a/infra/bots/recipes/swarm_ct_skps.expected/CT_IMG_DECODE_10k_SKPs_Trybot.json b/infra/bots/recipes/swarm_ct_skps.expected/CT_IMG_DECODE_10k_SKPs_Trybot.json
index 8b36687f61..4e449684bb 100644
--- a/infra/bots/recipes/swarm_ct_skps.expected/CT_IMG_DECODE_10k_SKPs_Trybot.json
+++ b/infra/bots/recipes/swarm_ct_skps.expected/CT_IMG_DECODE_10k_SKPs_Trybot.json
@@ -143,6 +143,8 @@
   },
   {
     "cmd": [
+      "python",
+      "-u",
       "[CUSTOM_/_B_WORK]/skia/bin/fetch-gn"
     ],
     "cwd": "[CUSTOM_/_B_WORK]/skia",