Auto merge of #12338 - upsuper:win-geckolib-fix, r=bholley

Fix geckolib build for Windows

It contains several fixes to make `./mach build-geckolib` work on Windows.

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components/style/build.rs

@@ -11,6 +11,10 @@ use walkdir::WalkDir;
 
 #[cfg(windows)]
 fn find_python() -> String {
+    if Command::new("python2.7.exe").arg("--version").output().is_ok() {
+        return "python2.7.exe".to_owned();
+    }
+
     if Command::new("python27.exe").arg("--version").output().is_ok() {
         return "python27.exe".to_owned();
     }
@@ -19,7 +23,8 @@ fn find_python() -> String {
         return "python.exe".to_owned();
     }
 
-    panic!("Can't find python (tried python27.exe and python.exe)! Try fixing PATH or setting the PYTHON env var");
+    panic!(concat!("Can't find python (tried python2.7.exe, python27.exe, and python.exe)! ",
+                   "Try fixing PATH or setting the PYTHON env var"));
 }
 
 #[cfg(not(windows))]

components/style/properties/build.py

@@ -6,7 +6,7 @@ import json
 import os.path
 import sys
 
-BASE = os.path.dirname(__file__)
+BASE = os.path.dirname(__file__.replace('\\', '/'))
 sys.path.insert(0, os.path.join(BASE, "Mako-0.9.1.zip"))
 sys.path.insert(0, BASE)  # For importing `data.py`
 

ports/geckolib/build.rs

@@ -8,6 +8,10 @@ use std::process::{Command, exit};
 
 #[cfg(windows)]
 fn find_python() -> String {
+    if Command::new("python2.7.exe").arg("--version").output().is_ok() {
+        return "python2.7.exe".to_owned();
+    }
+
     if Command::new("python27.exe").arg("--version").output().is_ok() {
         return "python27.exe".to_owned();
     }
@@ -16,7 +20,8 @@ fn find_python() -> String {
         return "python.exe".to_owned();
     }
 
-    panic!("Can't find python (tried python27.exe and python.exe)! Try fixing PATH or setting the PYTHON env var");
+    panic!(concat!("Can't find python (tried python2.7.exe, python27.exe, and python.exe)! ",
+                   "Try fixing PATH or setting the PYTHON env var"));
 }
 
 #[cfg(not(windows))]

python/servo/build_commands.py

@@ -368,9 +368,10 @@ class MachCommands(CommandBase):
             opts += ["--release"]
 
         build_start = time()
+        env = self.build_env()
         with cd(path.join("ports", "geckolib")):
             ret = call(["cargo", "build"] + opts,
-                       env=self.build_env(), verbose=verbose)
+                       env=env, verbose=verbose)
         elapsed = time() - build_start
 
         # Generate Desktop Notification if elapsed-time > some threshold value