Backport Mac installer fixes for git-based workflow (#2837)

Mac/BuildScript/build-installer.py

@@ -13,7 +13,7 @@ sphinx-build and the current versions of Sphinx now require at least
 Python 2.6.
 
 In addition to what is supplied with OS X 10.5+ and Xcode 3+, the script
-requires an installed version of hg and a third-party version of
+requires an installed third-party version of
 Tcl/Tk 8.4 (for OS X 10.4 and 10.5 deployment targets) or Tcl/TK 8.5
 (for 10.6 or later) installed in /Library/Frameworks.  When installed,
 the Python built by this script will attempt to dynamically link first to
@@ -23,7 +23,7 @@ installing the most recent ActiveTcl 8.4 or 8.5 version.
 
 32-bit-only installer builds are still possible on OS X 10.4 with Xcode 2.5
 and the installation of additional components, such as a newer Python
-(2.5 is needed for Python parser updates), hg, and for the documentation
+(2.5 is needed for Python parser updates) and for the documentation
 build either svn (pre-3.4.1) or sphinx-build (3.4.1 and later).
 
 Usage: see USAGE variable in the script.
@@ -577,7 +577,7 @@ def getTclTkVersion(configfile, versionline):
     """
     try:
         f = open(configfile, "r")
-    except:
+    except OSError:
         fatal("Framework configuration file not found: %s" % configfile)
 
     for l in f:
@@ -663,9 +663,8 @@ def checkEnvironment():
         base_path = base_path + ':' + OLD_DEVELOPER_TOOLS
     os.environ['PATH'] = base_path
     print("Setting default PATH: %s"%(os.environ['PATH']))
-    # Ensure ws have access to hg and to sphinx-build.
-    # You may have to create links in /usr/bin for them.
-    runCommand('hg --version')
+    # Ensure we have access to sphinx-build.
+    # You may have to create a link in /usr/bin for it.
     runCommand('sphinx-build --version')
 
 def parseOptions(args=None):
@@ -819,7 +818,7 @@ def downloadURL(url, fname):
     except:
         try:
             os.unlink(fname)
-        except:
+        except OSError:
             pass
 
 def verifyThirdPartyFile(url, checksum, fname):
@@ -1115,7 +1114,6 @@ def buildPythonDocs():
     docdir = os.path.join(rootDir, 'pydocs')
     curDir = os.getcwd()
     os.chdir(buildDir)
-    # The Doc build changed for 3.4 (technically, for 3.4.1) and for 2.7.9
     runCommand('make clean')
     # Assume sphinx-build is on our PATH, checked in checkEnvironment
     runCommand('make html')
@@ -1168,8 +1166,25 @@ def buildPython():
         shellQuote(WORKDIR)[1:-1],
         shellQuote(WORKDIR)[1:-1]))
 
-    print("Running make")
-    runCommand("make")
+    # Look for environment value BUILDINSTALLER_BUILDPYTHON_MAKE_EXTRAS
+    # and, if defined, append its value to the make command.  This allows
+    # us to pass in version control tags, like GITTAG, to a build from a
+    # tarball rather than from a vcs checkout, thus eliminating the need
+    # to have a working copy of the vcs program on the build machine.
+    #
+    # A typical use might be:
+    #      export BUILDINSTALLER_BUILDPYTHON_MAKE_EXTRAS=" \
+    #                         GITVERSION='echo 123456789a' \
+    #                         GITTAG='echo v3.6.0' \
+    #                         GITBRANCH='echo 3.6'"
+
+    make_extras = os.getenv("BUILDINSTALLER_BUILDPYTHON_MAKE_EXTRAS")
+    if make_extras:
+        make_cmd = "make " + make_extras
+    else:
+        make_cmd = "make"
+    print("Running " + make_cmd)
+    runCommand(make_cmd)
 
     print("Running make install")
     runCommand("make install DESTDIR=%s"%(