diff -r 1d71ce4531ac Include/pylifecycle.h
--- a/Include/pylifecycle.h	Sat Sep 10 16:19:45 2016 +0200
+++ b/Include/pylifecycle.h	Sat Sep 10 11:18:47 2016 -0700
@@ -72,6 +72,8 @@
 #ifndef Py_LIMITED_API
 PyAPI_FUNC(const char *) _Py_hgidentifier(void);
 PyAPI_FUNC(const char *) _Py_hgversion(void);
+PyAPI_FUNC(const char *) _Py_gitbranch(void);
+PyAPI_FUNC(const char *) _Py_gitversion(void);
 #endif
 
 /* Internal -- various one-time initializations */
diff -r 1d71ce4531ac Makefile.pre.in
--- a/Makefile.pre.in	Sat Sep 10 16:19:45 2016 +0200
+++ b/Makefile.pre.in	Sat Sep 10 11:18:47 2016 -0700
@@ -43,6 +43,8 @@
 HGVERSION=	@HGVERSION@
 HGTAG=		@HGTAG@
 HGBRANCH=	@HGBRANCH@
+GITVERSION= @GITVERSION@
+GITBRANCH=  @GITBRANCH@
 PGO_PROF_GEN_FLAG=@PGO_PROF_GEN_FLAG@
 PGO_PROF_USE_FLAG=@PGO_PROF_USE_FLAG@
 LLVM_PROF_MERGER=@LLVM_PROF_MERGER@
@@ -735,6 +737,8 @@
 	      -DHGVERSION="\"`LC_ALL=C $(HGVERSION)`\"" \
 	      -DHGTAG="\"`LC_ALL=C $(HGTAG)`\"" \
 	      -DHGBRANCH="\"`LC_ALL=C $(HGBRANCH)`\"" \
+		  -DGITVERSION="\"`LC_ALL=C $(GITVERSION)`\"" \
+		  -DGITBRANCH="\"`LC_ALL=C $(GITBRANCH)`\"" \
 	      -o $@ $(srcdir)/Modules/getbuildinfo.c
 
 Modules/getpath.o: $(srcdir)/Modules/getpath.c Makefile
diff -r 1d71ce4531ac Modules/getbuildinfo.c
--- a/Modules/getbuildinfo.c	Sat Sep 10 16:19:45 2016 +0200
+++ b/Modules/getbuildinfo.c	Sat Sep 10 11:18:47 2016 -0700
@@ -31,19 +31,35 @@
 #define HGBRANCH ""
 #endif
 
+#ifndef GITVERSION
+#define GITVERSION ""
+#endif
+#ifndef GITBRANCH
+#define GITBRANCH ""
+#endif
+
 const char *
 Py_GetBuildInfo(void)
 {
-    static char buildinfo[50 + sizeof(HGVERSION) +
+    static char buildinfo[50 +
+                          (sizeof(GITVERSION) ?
+                           sizeof(GITVERSION) : sizeof(HGVERSION)) +
+                          ((sizeof(GITVERSION) >
+                           (sizeof(HGTAG) + sizeof(HGBRANCH))) ?
+                           sizeof(GITVERSION) :
                           ((sizeof(HGTAG) > sizeof(HGBRANCH)) ?
-                           sizeof(HGTAG) : sizeof(HGBRANCH))];
-    const char *revision = _Py_hgversion();
+                           sizeof(HGTAG) : sizeof(HGBRANCH)))];
+    const char *revision = ((sizeof(HGVERSION) > sizeof(GITVERSION)) ?
+                            _Py_hgversion() : _Py_gitversion());
     const char *sep = *revision ? ":" : "";
-    const char *hgid = _Py_hgidentifier();
-    if (!(*hgid))
-        hgid = "default";
+    const char *id = ((sizeof(GITBRANCH) >
+                      (sizeof(HGTAG) + sizeof(HGBRANCH))) ?
+                      _Py_gitversion() : _Py_hgidentifier());
+    if (!(*id)) {
+        id = "default/tip";
+    }
     PyOS_snprintf(buildinfo, sizeof(buildinfo),
-                  "%s%s%s, %.20s, %.9s", hgid, sep, revision,
+                  "%s%s%s, %.20s, %.9s", id, sep, revision,
                   DATE, TIME);
     return buildinfo;
 }
@@ -65,3 +81,15 @@
         hgid = HGBRANCH;
     return hgid;
 }
+
+const char *
+_Py_gitversion(void)
+{
+    return GITVERSION;
+}
+
+const char *
+_Py_gitbranch(void)
+{
+    return GITBRANCH;
+}
diff -r 1d71ce4531ac Python/sysmodule.c
--- a/Python/sysmodule.c	Sat Sep 10 16:19:45 2016 +0200
+++ b/Python/sysmodule.c	Sat Sep 10 11:18:47 2016 -0700
@@ -1907,6 +1907,9 @@
     SET_SYS_FROM_STRING("_mercurial",
                         Py_BuildValue("(szz)", "CPython", _Py_hgidentifier(),
                                       _Py_hgversion()));
+    SET_SYS_FROM_STRING("_git",
+                        Py_BuildValue("(szz)", "CPython", _Py_gitbranch(),
+                                      _Py_gitversion()));
     SET_SYS_FROM_STRING("dont_write_bytecode",
                          PyBool_FromLong(Py_DontWriteBytecodeFlag));
     SET_SYS_FROM_STRING("api_version",
diff -r 1d71ce4531ac configure
--- a/configure	Sat Sep 10 16:19:45 2016 +0200
+++ b/configure	Sat Sep 10 11:18:47 2016 -0700
@@ -760,6 +760,9 @@
 build_vendor
 build_cpu
 build
+HAS_GIT
+GITBRANCH
+GITVERSION
 HAS_HG
 HGBRANCH
 HGTAG
@@ -2753,6 +2756,61 @@
 fi
 
 
+
+
+if test -e $srcdir/.git/HEAD
+then
+# Extract the first word of "git", so it can be a program name with args.
+set dummy git; ac_word=$2
+{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for $ac_word" >&5
+$as_echo_n "checking for $ac_word... " >&6; }
+if ${ac_cv_prog_HAS_GIT+:} false; then :
+  $as_echo_n "(cached) " >&6
+else
+  if test -n "$HAS_GIT"; then
+  ac_cv_prog_HAS_GIT="$HAS_GIT" # Let the user override the test.
+else
+as_save_IFS=$IFS; IFS=$PATH_SEPARATOR
+for as_dir in $PATH
+do
+  IFS=$as_save_IFS
+  test -z "$as_dir" && as_dir=.
+    for ac_exec_ext in '' $ac_executable_extensions; do
+  if as_fn_executable_p "$as_dir/$ac_word$ac_exec_ext"; then
+    ac_cv_prog_HAS_GIT="found"
+    $as_echo "$as_me:${as_lineno-$LINENO}: found $as_dir/$ac_word$ac_exec_ext" >&5
+    break 2
+  fi
+done
+  done
+IFS=$as_save_IFS
+
+  test -z "$ac_cv_prog_HAS_GIT" && ac_cv_prog_HAS_GIT="not-found"
+fi
+fi
+HAS_GIT=$ac_cv_prog_HAS_GIT
+if test -n "$HAS_GIT"; then
+  { $as_echo "$as_me:${as_lineno-$LINENO}: result: $HAS_GIT" >&5
+$as_echo "$HAS_GIT" >&6; }
+else
+  { $as_echo "$as_me:${as_lineno-$LINENO}: result: no" >&5
+$as_echo "no" >&6; }
+fi
+
+
+else
+HAS_GIT=no-repository
+fi
+if test $HAS_GIT = found
+then
+    GITVERSION="git -C \$(srcdir) rev-parse HEAD"
+    GITBRANCH="git -C \$(srcdir) rev-parse --abbrev-ref HEAD"
+else
+    GITVERSION=""
+    GITBRANCH=""
+fi
+
+
 ac_config_headers="$ac_config_headers pyconfig.h"
 
 
diff -r 1d71ce4531ac configure.ac
--- a/configure.ac	Sat Sep 10 16:19:45 2016 +0200
+++ b/configure.ac	Sat Sep 10 11:18:47 2016 -0700
@@ -46,6 +46,24 @@
     HGBRANCH=""
 fi
 
+AC_SUBST(GITVERSION)
+AC_SUBST(GITBRANCH)
+
+if test -e $srcdir/.git/HEAD
+then
+AC_CHECK_PROG(HAS_GIT, git, found, not-found)
+else
+HAS_GIT=no-repository
+fi
+if test $HAS_GIT = found
+then
+    GITVERSION="git -C \$(srcdir) rev-parse HEAD"
+    GITBRANCH="git -C \$(srcdir) rev-parse --abbrev-ref HEAD"
+else
+    GITVERSION=""
+    GITBRANCH=""
+fi
+
 AC_CONFIG_SRCDIR([Include/object.h])
 AC_CONFIG_HEADER(pyconfig.h)