From 7e0fcaa5b28eb1aa022a59e5056679e7854070b9 Mon Sep 17 00:00:00 2001
From: Rob Browning <rlb@defaultvalue.org>
Date: Sat, 12 Dec 2015 13:30:18 -0600
Subject: [PATCH] Configure python, use it, and embed during install

Search for a "reasonable" python in ./configure (or respect PYTHON), and
use that to create a source tree cmd/python-cmd.sh that all of the
relevant invocations in the source tree respect.

During install, rewrite all of the relevant #! lines to refer to the
./configure selected Python.

Signed-off-by: Rob Browning <rlb@defaultvalue.org>
Tested-by: Rob Browning <rlb@defaultvalue.org>
---
 Makefile                    | 21 ++++++++++++++++-----
 README.md                   |  6 ++++++
 cmd/bloom-cmd.py            |  7 ++++++-
 cmd/cat-file-cmd.py         |  7 ++++++-
 cmd/daemon-cmd.py           |  7 ++++++-
 cmd/damage-cmd.py           |  7 ++++++-
 cmd/drecurse-cmd.py         |  7 ++++++-
 cmd/fsck-cmd.py             |  7 ++++++-
 cmd/ftp-cmd.py              |  7 ++++++-
 cmd/fuse-cmd.py             |  7 ++++++-
 cmd/help-cmd.py             |  7 ++++++-
 cmd/import-duplicity-cmd.py |  7 ++++++-
 cmd/index-cmd.py            |  7 ++++++-
 cmd/init-cmd.py             |  7 ++++++-
 cmd/join-cmd.py             |  7 ++++++-
 cmd/list-idx-cmd.py         |  7 ++++++-
 cmd/ls-cmd.py               |  7 ++++++-
 cmd/margin-cmd.py           |  7 ++++++-
 cmd/memtest-cmd.py          |  7 ++++++-
 cmd/meta-cmd.py             |  7 ++++++-
 cmd/midx-cmd.py             |  7 ++++++-
 cmd/mux-cmd.py              |  7 ++++++-
 cmd/newliner-cmd.py         |  7 ++++++-
 cmd/on--server-cmd.py       |  7 ++++++-
 cmd/on-cmd.py               |  7 ++++++-
 cmd/random-cmd.py           |  7 ++++++-
 cmd/restore-cmd.py          |  7 ++++++-
 cmd/save-cmd.py             |  7 ++++++-
 cmd/server-cmd.py           |  7 ++++++-
 cmd/split-cmd.py            |  7 ++++++-
 cmd/tag-cmd.py              |  7 ++++++-
 cmd/tick-cmd.py             |  7 ++++++-
 cmd/version-cmd.py          |  7 ++++++-
 cmd/web-cmd.py              |  7 ++++++-
 cmd/xstat-cmd.py            |  7 ++++++-
 config/configure            | 12 +++++++++++-
 main.py                     |  8 +++++++-
 t/cleanup-mounts-under      |  3 +++
 t/hardlink-sets             |  7 ++++++-
 t/id-other-than             |  7 ++++++-
 t/mksock                    |  7 ++++++-
 t/ns-timestamp-resolutions  |  7 ++++++-
 t/root-status               |  7 ++++++-
 t/subtree-hash              |  7 ++++++-
 t/unknown-owner             |  7 ++++++-
 wvtest.py                   |  7 ++++++-
 46 files changed, 289 insertions(+), 48 deletions(-)

diff --git a/Makefile b/Makefile
index daefc08..e49f80d 100644
--- a/Makefile
+++ b/Makefile
@@ -30,8 +30,15 @@ Documentation/all: $(bup_deps)
 $(current_sampledata):
 	t/configure-sampledata --setup
 
+PYTHON = $(shell cmd/bup-python -c 'import sys; print sys.executable')
+
+define install-python-bin
+  set -e; \
+  sed -e '1 s|.*|#!$(PYTHON)|; 2,/^# end of bup preamble$$/d' $1 > $2; \
+  chmod 0755 $2;
+endef
+
 INSTALL=install
-PYTHON=python
 PREFIX=/usr
 MANDIR=$(DESTDIR)$(PREFIX)/share/man
 DOCDIR=$(DESTDIR)$(PREFIX)/share/doc/bup
@@ -49,10 +56,11 @@ install: all
 	  $(INSTALL) -m 0644 \
 		Documentation/*.html \
 		$(DOCDIR)
-	$(INSTALL) -pm 0755 bup $(BINDIR)
-	$(INSTALL) -pm 0755 \
-		cmd/bup-* \
-		$(LIBDIR)/cmd
+	$(call install-python-bin,bup,"$(BINDIR)/bup")
+	set -e; \
+	for cmd in $$(ls cmd/bup-* | grep -v cmd/bup-python); do \
+	  $(call install-python-bin,"$$cmd","$(LIBDIR)/$$cmd") \
+	done
 	$(INSTALL) -pm 0644 \
 		lib/bup/*.py \
 		$(LIBDIR)/bup
@@ -143,6 +151,9 @@ test: all
 
 check: test
 
+cmd/python-cmd.sh: config/configure
+	./config/configure
+
 cmds: \
     $(patsubst cmd/%-cmd.py,cmd/bup-%,$(wildcard cmd/*-cmd.py)) \
     $(patsubst cmd/%-cmd.sh,cmd/bup-%,$(wildcard cmd/*-cmd.sh))
diff --git a/README.md b/README.md
index 7eb4c2d..01c2e5d 100644
--- a/README.md
+++ b/README.md
@@ -154,6 +154,12 @@ From source
 
         make install DESTDIR=/opt/bup PREFIX=''
 
+ - The Python executable that bup will use is chosen by ./configure,
+   which will search for a reasonable version unless PYTHON is set in
+   the environment, in which case, bup will use that path.  You can
+   see which Python executable was chosen by looking at the
+   configure output, or examining cmd/python-cmd.sh, and you can
+   change the selection by re-running ./configure.
 
 From binary packages
 --------------------
diff --git a/cmd/bloom-cmd.py b/cmd/bloom-cmd.py
index cd4506d..b2f909b 100755
--- a/cmd/bloom-cmd.py
+++ b/cmd/bloom-cmd.py
@@ -1,4 +1,9 @@
-#!/usr/bin/env python
+#!/bin/sh
+"""": # -*-python-*-
+bup_python="$(dirname "$0")/bup-python" || exit $?
+exec "$bup_python" "$0" ${1+"$@"}
+"""
+# end of bup preamble
 import sys, glob, tempfile
 from bup import options, git, bloom
 from bup.helpers import *
diff --git a/cmd/cat-file-cmd.py b/cmd/cat-file-cmd.py
index 8948ff2..735a239 100755
--- a/cmd/cat-file-cmd.py
+++ b/cmd/cat-file-cmd.py
@@ -1,4 +1,9 @@
-#!/usr/bin/env python
+#!/bin/sh
+"""": # -*-python-*-
+bup_python="$(dirname "$0")/bup-python" || exit $?
+exec "$bup_python" "$0" ${1+"$@"}
+"""
+# end of bup preamble
 import sys, stat
 from bup import options, git, vfs
 from bup.helpers import *
diff --git a/cmd/daemon-cmd.py b/cmd/daemon-cmd.py
index c90e3e4..5149c16 100755
--- a/cmd/daemon-cmd.py
+++ b/cmd/daemon-cmd.py
@@ -1,4 +1,9 @@
-#!/usr/bin/env python
+#!/bin/sh
+"""": # -*-python-*-
+bup_python="$(dirname "$0")/bup-python" || exit $?
+exec "$bup_python" "$0" ${1+"$@"}
+"""
+# end of bup preamble
 import sys, getopt, socket, subprocess, fcntl
 from bup import options, path
 from bup.helpers import *
diff --git a/cmd/damage-cmd.py b/cmd/damage-cmd.py
index 49dbed0..22bc8f0 100755
--- a/cmd/damage-cmd.py
+++ b/cmd/damage-cmd.py
@@ -1,4 +1,9 @@
-#!/usr/bin/env python
+#!/bin/sh
+"""": # -*-python-*-
+bup_python="$(dirname "$0")/bup-python" || exit $?
+exec "$bup_python" "$0" ${1+"$@"}
+"""
+# end of bup preamble
 import sys, os, random
 from bup import options
 from bup.helpers import *
diff --git a/cmd/drecurse-cmd.py b/cmd/drecurse-cmd.py
index cdf6680..611bfdb 100755
--- a/cmd/drecurse-cmd.py
+++ b/cmd/drecurse-cmd.py
@@ -1,4 +1,9 @@
-#!/usr/bin/env python
+#!/bin/sh
+"""": # -*-python-*-
+bup_python="$(dirname "$0")/bup-python" || exit $?
+exec "$bup_python" "$0" ${1+"$@"}
+"""
+# end of bup preamble
 
 from os.path import relpath
 from bup import options, drecurse
diff --git a/cmd/fsck-cmd.py b/cmd/fsck-cmd.py
index 794c755..a5ab754 100755
--- a/cmd/fsck-cmd.py
+++ b/cmd/fsck-cmd.py
@@ -1,4 +1,9 @@
-#!/usr/bin/env python
+#!/bin/sh
+"""": # -*-python-*-
+bup_python="$(dirname "$0")/bup-python" || exit $?
+exec "$bup_python" "$0" ${1+"$@"}
+"""
+# end of bup preamble
 import sys, os, glob, subprocess
 from bup import options, git
 from bup.helpers import *
diff --git a/cmd/ftp-cmd.py b/cmd/ftp-cmd.py
index baa1e08..1935266 100755
--- a/cmd/ftp-cmd.py
+++ b/cmd/ftp-cmd.py
@@ -1,4 +1,9 @@
-#!/usr/bin/env python
+#!/bin/sh
+"""": # -*-python-*-
+bup_python="$(dirname "$0")/bup-python" || exit $?
+exec "$bup_python" "$0" ${1+"$@"}
+"""
+# end of bup preamble
 import sys, os, stat, fnmatch
 from bup import options, git, shquote, vfs, ls
 from bup.helpers import *
diff --git a/cmd/fuse-cmd.py b/cmd/fuse-cmd.py
index 30776cb..3708692 100755
--- a/cmd/fuse-cmd.py
+++ b/cmd/fuse-cmd.py
@@ -1,4 +1,9 @@
-#!/usr/bin/env python
+#!/bin/sh
+"""": # -*-python-*-
+bup_python="$(dirname "$0")/bup-python" || exit $?
+exec "$bup_python" "$0" ${1+"$@"}
+"""
+# end of bup preamble
 import sys, os, errno
 from bup import options, git, vfs, xstat
 from bup.helpers import *
diff --git a/cmd/help-cmd.py b/cmd/help-cmd.py
index 56a4148..2efc729 100755
--- a/cmd/help-cmd.py
+++ b/cmd/help-cmd.py
@@ -1,4 +1,9 @@
-#!/usr/bin/env python
+#!/bin/sh
+"""": # -*-python-*-
+bup_python="$(dirname "$0")/bup-python" || exit $?
+exec "$bup_python" "$0" ${1+"$@"}
+"""
+# end of bup preamble
 import sys, os, glob
 from bup import options, path
 
diff --git a/cmd/import-duplicity-cmd.py b/cmd/import-duplicity-cmd.py
index 163d4fa..ff37daf 100755
--- a/cmd/import-duplicity-cmd.py
+++ b/cmd/import-duplicity-cmd.py
@@ -1,4 +1,9 @@
-#!/usr/bin/env python
+#!/bin/sh
+"""": # -*-python-*-
+bup_python="$(dirname "$0")/bup-python" || exit $?
+exec "$bup_python" "$0" ${1+"$@"}
+"""
+# end of bup preamble
 
 from calendar import timegm
 from pipes import quote
diff --git a/cmd/index-cmd.py b/cmd/index-cmd.py
index 6f2adf4..e416ac5 100755
--- a/cmd/index-cmd.py
+++ b/cmd/index-cmd.py
@@ -1,4 +1,9 @@
-#!/usr/bin/env python
+#!/bin/sh
+"""": # -*-python-*-
+bup_python="$(dirname "$0")/bup-python" || exit $?
+exec "$bup_python" "$0" ${1+"$@"}
+"""
+# end of bup preamble
 
 import sys, stat, time, os, errno, re
 from bup import metadata, options, git, index, drecurse, hlinkdb
diff --git a/cmd/init-cmd.py b/cmd/init-cmd.py
index 2e4a151..e6cc6b5 100755
--- a/cmd/init-cmd.py
+++ b/cmd/init-cmd.py
@@ -1,4 +1,9 @@
-#!/usr/bin/env python
+#!/bin/sh
+"""": # -*-python-*-
+bup_python="$(dirname "$0")/bup-python" || exit $?
+exec "$bup_python" "$0" ${1+"$@"}
+"""
+# end of bup preamble
 import sys
 
 from bup import git, options, client
diff --git a/cmd/join-cmd.py b/cmd/join-cmd.py
index 042b402..347206d 100755
--- a/cmd/join-cmd.py
+++ b/cmd/join-cmd.py
@@ -1,4 +1,9 @@
-#!/usr/bin/env python
+#!/bin/sh
+"""": # -*-python-*-
+bup_python="$(dirname "$0")/bup-python" || exit $?
+exec "$bup_python" "$0" ${1+"$@"}
+"""
+# end of bup preamble
 import sys
 from bup import git, options, client
 from bup.helpers import *
diff --git a/cmd/list-idx-cmd.py b/cmd/list-idx-cmd.py
index a3e3dc9..9eb92c1 100755
--- a/cmd/list-idx-cmd.py
+++ b/cmd/list-idx-cmd.py
@@ -1,4 +1,9 @@
-#!/usr/bin/env python
+#!/bin/sh
+"""": # -*-python-*-
+bup_python="$(dirname "$0")/bup-python" || exit $?
+exec "$bup_python" "$0" ${1+"$@"}
+"""
+# end of bup preamble
 import sys, os
 from bup import git, options
 from bup.helpers import *
diff --git a/cmd/ls-cmd.py b/cmd/ls-cmd.py
index 94a7131..031fbae 100755
--- a/cmd/ls-cmd.py
+++ b/cmd/ls-cmd.py
@@ -1,4 +1,9 @@
-#!/usr/bin/env python
+#!/bin/sh
+"""": # -*-python-*-
+bup_python="$(dirname "$0")/bup-python" || exit $?
+exec "$bup_python" "$0" ${1+"$@"}
+"""
+# end of bup preamble
 import sys
 from bup import git, vfs, ls
 from bup.helpers import *
diff --git a/cmd/margin-cmd.py b/cmd/margin-cmd.py
index 9b7fd60..ac25ed0 100755
--- a/cmd/margin-cmd.py
+++ b/cmd/margin-cmd.py
@@ -1,4 +1,9 @@
-#!/usr/bin/env python
+#!/bin/sh
+"""": # -*-python-*-
+bup_python="$(dirname "$0")/bup-python" || exit $?
+exec "$bup_python" "$0" ${1+"$@"}
+"""
+# end of bup preamble
 import sys, struct, math
 from bup import options, git, _helpers
 from bup.helpers import *
diff --git a/cmd/memtest-cmd.py b/cmd/memtest-cmd.py
index 0e3cf0c..65778b7 100755
--- a/cmd/memtest-cmd.py
+++ b/cmd/memtest-cmd.py
@@ -1,4 +1,9 @@
-#!/usr/bin/env python
+#!/bin/sh
+"""": # -*-python-*-
+bup_python="$(dirname "$0")/bup-python" || exit $?
+exec "$bup_python" "$0" ${1+"$@"}
+"""
+# end of bup preamble
 import sys, re, struct, time, resource
 from bup import git, bloom, midx, options, _helpers
 from bup.helpers import *
diff --git a/cmd/meta-cmd.py b/cmd/meta-cmd.py
index cac26b5..671abce 100755
--- a/cmd/meta-cmd.py
+++ b/cmd/meta-cmd.py
@@ -1,4 +1,9 @@
-#!/usr/bin/env python
+#!/bin/sh
+"""": # -*-python-*-
+bup_python="$(dirname "$0")/bup-python" || exit $?
+exec "$bup_python" "$0" ${1+"$@"}
+"""
+# end of bup preamble
 
 # Copyright (C) 2010 Rob Browning
 #
diff --git a/cmd/midx-cmd.py b/cmd/midx-cmd.py
index 6876751..eb558f8 100755
--- a/cmd/midx-cmd.py
+++ b/cmd/midx-cmd.py
@@ -1,4 +1,9 @@
-#!/usr/bin/env python
+#!/bin/sh
+"""": # -*-python-*-
+bup_python="$(dirname "$0")/bup-python" || exit $?
+exec "$bup_python" "$0" ${1+"$@"}
+"""
+# end of bup preamble
 import sys, math, struct, glob, resource
 import tempfile
 from bup import options, git, midx, _helpers, xstat
diff --git a/cmd/mux-cmd.py b/cmd/mux-cmd.py
index b70c0a8..7a8a9ea 100755
--- a/cmd/mux-cmd.py
+++ b/cmd/mux-cmd.py
@@ -1,4 +1,9 @@
-#!/usr/bin/env python
+#!/bin/sh
+"""": # -*-python-*-
+bup_python="$(dirname "$0")/bup-python" || exit $?
+exec "$bup_python" "$0" ${1+"$@"}
+"""
+# end of bup preamble
 import os, sys, subprocess, struct
 from bup import options
 from bup.helpers import *
diff --git a/cmd/newliner-cmd.py b/cmd/newliner-cmd.py
index 68d327b..20027ab 100755
--- a/cmd/newliner-cmd.py
+++ b/cmd/newliner-cmd.py
@@ -1,4 +1,9 @@
-#!/usr/bin/env python
+#!/bin/sh
+"""": # -*-python-*-
+bup_python="$(dirname "$0")/bup-python" || exit $?
+exec "$bup_python" "$0" ${1+"$@"}
+"""
+# end of bup preamble
 import sys, os, re
 from bup import options
 from bup import _helpers   # fixes up sys.argv on import
diff --git a/cmd/on--server-cmd.py b/cmd/on--server-cmd.py
index a6f3e21..cdfd441 100755
--- a/cmd/on--server-cmd.py
+++ b/cmd/on--server-cmd.py
@@ -1,4 +1,9 @@
-#!/usr/bin/env python
+#!/bin/sh
+"""": # -*-python-*-
+bup_python="$(dirname "$0")/bup-python" || exit $?
+exec "$bup_python" "$0" ${1+"$@"}
+"""
+# end of bup preamble
 import sys, os, struct
 from bup import options, helpers
 
diff --git a/cmd/on-cmd.py b/cmd/on-cmd.py
index 9d6f683..df0fdb3 100755
--- a/cmd/on-cmd.py
+++ b/cmd/on-cmd.py
@@ -1,4 +1,9 @@
-#!/usr/bin/env python
+#!/bin/sh
+"""": # -*-python-*-
+bup_python="$(dirname "$0")/bup-python" || exit $?
+exec "$bup_python" "$0" ${1+"$@"}
+"""
+# end of bup preamble
 import sys, os, struct, getopt, subprocess, signal
 from subprocess import PIPE
 from bup import options, ssh, path
diff --git a/cmd/random-cmd.py b/cmd/random-cmd.py
index 4be3660..7d4c007 100755
--- a/cmd/random-cmd.py
+++ b/cmd/random-cmd.py
@@ -1,4 +1,9 @@
-#!/usr/bin/env python
+#!/bin/sh
+"""": # -*-python-*-
+bup_python="$(dirname "$0")/bup-python" || exit $?
+exec "$bup_python" "$0" ${1+"$@"}
+"""
+# end of bup preamble
 import sys
 from bup import options, _helpers
 from bup.helpers import *
diff --git a/cmd/restore-cmd.py b/cmd/restore-cmd.py
index d527489..c7f446b 100755
--- a/cmd/restore-cmd.py
+++ b/cmd/restore-cmd.py
@@ -1,4 +1,9 @@
-#!/usr/bin/env python
+#!/bin/sh
+"""": # -*-python-*-
+bup_python="$(dirname "$0")/bup-python" || exit $?
+exec "$bup_python" "$0" ${1+"$@"}
+"""
+# end of bup preamble
 import copy, errno, sys, stat, re
 from bup import options, git, metadata, vfs
 from bup.helpers import *
diff --git a/cmd/save-cmd.py b/cmd/save-cmd.py
index fc93408..664b580 100755
--- a/cmd/save-cmd.py
+++ b/cmd/save-cmd.py
@@ -1,4 +1,9 @@
-#!/usr/bin/env python
+#!/bin/sh
+"""": # -*-python-*-
+bup_python="$(dirname "$0")/bup-python" || exit $?
+exec "$bup_python" "$0" ${1+"$@"}
+"""
+# end of bup preamble
 import sys, stat, time, math
 from cStringIO import StringIO
 from errno import EACCES
diff --git a/cmd/server-cmd.py b/cmd/server-cmd.py
index 43a3fce..cf7be26 100755
--- a/cmd/server-cmd.py
+++ b/cmd/server-cmd.py
@@ -1,4 +1,9 @@
-#!/usr/bin/env python
+#!/bin/sh
+"""": # -*-python-*-
+bup_python="$(dirname "$0")/bup-python" || exit $?
+exec "$bup_python" "$0" ${1+"$@"}
+"""
+# end of bup preamble
 import os, sys, struct
 from bup import options, git
 from bup.helpers import *
diff --git a/cmd/split-cmd.py b/cmd/split-cmd.py
index 70daf7c..b7c7c86 100755
--- a/cmd/split-cmd.py
+++ b/cmd/split-cmd.py
@@ -1,4 +1,9 @@
-#!/usr/bin/env python
+#!/bin/sh
+"""": # -*-python-*-
+bup_python="$(dirname "$0")/bup-python" || exit $?
+exec "$bup_python" "$0" ${1+"$@"}
+"""
+# end of bup preamble
 import os, sys, time
 from bup import hashsplit, git, options, client
 from bup.helpers import *
diff --git a/cmd/tag-cmd.py b/cmd/tag-cmd.py
index f33855e..f12ea4e 100755
--- a/cmd/tag-cmd.py
+++ b/cmd/tag-cmd.py
@@ -1,4 +1,9 @@
-#!/usr/bin/env python
+#!/bin/sh
+"""": # -*-python-*-
+bup_python="$(dirname "$0")/bup-python" || exit $?
+exec "$bup_python" "$0" ${1+"$@"}
+"""
+# end of bup preamble
 
 import sys
 import os
diff --git a/cmd/tick-cmd.py b/cmd/tick-cmd.py
index 4d462ad..ce3d399 100755
--- a/cmd/tick-cmd.py
+++ b/cmd/tick-cmd.py
@@ -1,4 +1,9 @@
-#!/usr/bin/env python
+#!/bin/sh
+"""": # -*-python-*-
+bup_python="$(dirname "$0")/bup-python" || exit $?
+exec "$bup_python" "$0" ${1+"$@"}
+"""
+# end of bup preamble
 import sys, time
 from bup import options
 
diff --git a/cmd/version-cmd.py b/cmd/version-cmd.py
index 645f25f..fbbe24f 100755
--- a/cmd/version-cmd.py
+++ b/cmd/version-cmd.py
@@ -1,4 +1,9 @@
-#!/usr/bin/env python
+#!/bin/sh
+"""": # -*-python-*-
+bup_python="$(dirname "$0")/bup-python" || exit $?
+exec "$bup_python" "$0" ${1+"$@"}
+"""
+# end of bup preamble
 import sys
 from bup import options
 from bup import _version
diff --git a/cmd/web-cmd.py b/cmd/web-cmd.py
index 1c515e2..acbbb80 100755
--- a/cmd/web-cmd.py
+++ b/cmd/web-cmd.py
@@ -1,4 +1,9 @@
-#!/usr/bin/env python
+#!/bin/sh
+"""": # -*-python-*-
+bup_python="$(dirname "$0")/bup-python" || exit $?
+exec "$bup_python" "$0" ${1+"$@"}
+"""
+# end of bup preamble
 import sys, stat, urllib, mimetypes, posixpath, time, webbrowser
 import urllib
 from bup import options, git, vfs
diff --git a/cmd/xstat-cmd.py b/cmd/xstat-cmd.py
index 85071d2..c977d1c 100755
--- a/cmd/xstat-cmd.py
+++ b/cmd/xstat-cmd.py
@@ -1,4 +1,9 @@
-#!/usr/bin/env python
+#!/bin/sh
+"""": # -*-python-*-
+bup_python="$(dirname "$0")/bup-python" || exit $?
+exec "$bup_python" "$0" ${1+"$@"}
+"""
+# end of bup preamble
 # Copyright (C) 2010 Rob Browning
 #
 # This code is covered under the terms of the GNU Library General
diff --git a/config/configure b/config/configure
index 8003241..a2afb83 100755
--- a/config/configure
+++ b/config/configure
@@ -56,8 +56,18 @@ if [ -z "$MAKE_VERSION" ]; then
 fi
 expr "$MAKE_VERSION" '>=' '3.81' || AC_FAIL "ERROR: $MAKE must be >= version 3.81"
 
-if test -z "$(bup_find_prog python '')"; then
+bup_python="$PYTHON"
+test -z "$bup_python" && bup_python="$(bup_find_prog python2.7 '')"
+test -z "$bup_python" && bup_python="$(bup_find_prog python2.6 '')"
+test -z "$bup_python" && bup_python="$(bup_find_prog python2 '')"
+test -z "$bup_python" && bup_python="$(bup_find_prog python '')"
+if test -z "$bup_python"; then
     AC_FAIL "ERROR: unable to find python"
+else
+    echo "#!/bin/sh" > ../cmd/python-cmd.sh
+    printf "exec %q \"\$@\"" "$bup_python" >> ../cmd/python-cmd.sh
+    chmod u+x ../cmd/python-cmd.sh
+    cd ../cmd && ln -sf python-cmd.sh bup-python
 fi
 
 if test -z "$(bup_find_prog git '')"; then
diff --git a/main.py b/main.py
index 45a0e8a..ef22957 100755
--- a/main.py
+++ b/main.py
@@ -1,4 +1,10 @@
-#!/usr/bin/env python
+#!/bin/sh
+"""": # -*-python-*- # -*-python-*-
+bup_python="$(dirname "$0")/cmd/bup-python" || exit $?
+exec "$bup_python" "$0" ${1+"$@"}
+"""
+# end of bup preamble
+
 import sys, os, subprocess, signal, getopt
 
 argv = sys.argv
diff --git a/t/cleanup-mounts-under b/t/cleanup-mounts-under
index a8ba611..9a72ded 100755
--- a/t/cleanup-mounts-under
+++ b/t/cleanup-mounts-under
@@ -1,5 +1,8 @@
 #!/usr/bin/env python
 
+# This cannot rely on bup-python because it runs during clean, and so
+# it also needs to be compatible with Python 2 and 3.
+
 import os.path, re, subprocess, sys
 
 def mntent_unescape(x):
diff --git a/t/hardlink-sets b/t/hardlink-sets
index 653b4d2..9dffe14 100755
--- a/t/hardlink-sets
+++ b/t/hardlink-sets
@@ -1,4 +1,9 @@
-#!/usr/bin/env python
+#!/bin/sh
+"""": # -*-python-*-
+bup_python="$(dirname "$0")/../cmd/bup-python" || exit $?
+exec "$bup_python" "$0" ${1+"$@"}
+"""
+# end of bup preamble
 
 import os, stat, sys
 
diff --git a/t/id-other-than b/t/id-other-than
index cfa219d..2c0370f 100755
--- a/t/id-other-than
+++ b/t/id-other-than
@@ -1,4 +1,9 @@
-#!/usr/bin/env python
+#!/bin/sh
+"""": # -*-python-*-
+bup_python="$(dirname "$0")/../cmd/bup-python" || exit $?
+exec "$bup_python" "$0" ${1+"$@"}
+"""
+# end of bup preamble
 
 import grp
 import pwd
diff --git a/t/mksock b/t/mksock
index ee2dbfe..6fb19d8 100755
--- a/t/mksock
+++ b/t/mksock
@@ -1,4 +1,9 @@
-#!/usr/bin/env python
+#!/bin/sh
+"""": # -*-python-*-
+bup_python="$(dirname "$0")/../cmd/bup-python" || exit $?
+exec "$bup_python" "$0" ${1+"$@"}
+"""
+# end of bup preamble
 
 import socket, sys
 
diff --git a/t/ns-timestamp-resolutions b/t/ns-timestamp-resolutions
index d1bb785..0763127 100755
--- a/t/ns-timestamp-resolutions
+++ b/t/ns-timestamp-resolutions
@@ -1,4 +1,9 @@
-#!/usr/bin/env python
+#!/bin/sh
+"""": # -*-python-*-
+bup_python="$(dirname "$0")/../cmd/bup-python" || exit $?
+exec "$bup_python" "$0" ${1+"$@"}
+"""
+# end of bup preamble
 
 import os, sys
 
diff --git a/t/root-status b/t/root-status
index 9fb12cb..5024ed3 100755
--- a/t/root-status
+++ b/t/root-status
@@ -1,4 +1,9 @@
-#!/usr/bin/env python
+#!/bin/sh
+"""": # -*-python-*-
+bup_python="$(dirname "$0")/../cmd/bup-python" || exit $?
+exec "$bup_python" "$0" ${1+"$@"}
+"""
+# end of bup preamble
 
 import sys
 
diff --git a/t/subtree-hash b/t/subtree-hash
index 691c207..926303f 100755
--- a/t/subtree-hash
+++ b/t/subtree-hash
@@ -1,4 +1,9 @@
-#!/usr/bin/env python
+#!/bin/sh
+"""": # -*-python-*-
+bup_python="$(dirname "$0")/../cmd/bup-python" || exit $?
+exec "$bup_python" "$0" ${1+"$@"}
+"""
+# end of bup preamble
 
 import os, sys
 
diff --git a/t/unknown-owner b/t/unknown-owner
index 00442a4..210c5b3 100755
--- a/t/unknown-owner
+++ b/t/unknown-owner
@@ -1,4 +1,9 @@
-#!/usr/bin/env python
+#!/bin/sh
+"""": # -*-python-*-
+bup_python="$(dirname "$0")/../cmd/bup-python" || exit $?
+exec "$bup_python" "$0" ${1+"$@"}
+"""
+# end of bup preamble
 
 import grp
 import pwd
diff --git a/wvtest.py b/wvtest.py
index cc68601..bdd1d79 100755
--- a/wvtest.py
+++ b/wvtest.py
@@ -1,4 +1,9 @@
-#!/usr/bin/env python
+#!/bin/sh
+"""": # -*-python-*-
+export PATH="$(dirname "$0")/cmd:$PATH"
+exec "$bup_python" "$0" ${1+"$@"}
+"""
+# end of bup preamble
 #
 # WvTest:
 #   Copyright (C)2007-2012 Versabanq Innovations Inc. and contributors.
-- 
2.39.2