Prefer python 3, and mention intent to drop python 2 support

For now, set the minimum supported 3 version at 3.7 since I just
tested that on a debian/buster system, and update the installation
instructions after seeing what was required to run the tests from
scratch there.  Continue to search for 3.6 and 2.6 for now, since no
one's complained, and we can always lower the requirement later if it
seems appropriate.

Signed-off-by: Rob Browning <rlb@defaultvalue.org>
Tested-by: Rob Browning <rlb@defaultvalue.org>

diff --git a/README.md b/README.md
index 1e4022e8cdf098a7fc8c1f2f3f61ac0633188d92..6c15ffe04b4d2d77574d6aa4f37c2a7f5d2d48ff 100644 (file)
--- a/README.md
+++ b/README.md
@@ -71,10 +71,12 @@ Reasons you might want to avoid bup
    more likely to eat your data.  It's also missing some
    probably-critical features, though fewer than it used to be.
    
- - It requires python >= 2.6, a C compiler, and an installed git
-   version >= 1.5.6.  It also requires par2 if you want fsck to be
-   able to generate the information needed to recover from some types
-   of corruption.
+ - It requires python 3.7 or newer (or 2.7 for a bit longer), a C
+   compiler, and an installed git version >= 1.5.6.  It also requires
+   par2 if you want fsck to be able to generate the information needed
+   to recover from some types of corruption.  While python 2.7 is
+   still supported, please make plans to upgrade.  Python 2 upstream
+   support ended on 2020-01-01, and we plan to drop support soon too.
  
  - It currently only works on Linux, FreeBSD, NetBSD, OS X >= 10.4,
    Solaris, or Windows (with Cygwin, and WSL).  Patches to support
@@ -86,7 +88,6 @@ Reasons you might want to avoid bup
 
  - Any items in "Things that are stupid" below.
 
-
 Notable changes introduced by a release
 =======================================
 
@@ -128,7 +129,7 @@ From source
    bup, please check out the latest stable release like this:
 
     ```sh
-    git checkout 0.29.1
+    git checkout 0.31
     ```
 
    You can see the latest stable release here:
@@ -144,15 +145,29 @@ From source
     apt-get build-dep bup
     ```
 
-   Otherwise try this (substitute python2.6-dev if you have an older
-   system):
+   Otherwise try this:
+
+    ```sh
+    apt-get install python3.7-dev python3-fuse
+    apt-get install python3-pyxattr python3-pytest
+    apt-get install python3-distutils
+    apt-get install pkg-config linux-libc-dev libacl1-dev
+    apt-get install gcc make acl attr rsync
+    apt-get isntall python3-pytest-xdist # optional (parallel tests)
+    apt-get install par2 # optional (error correction)
+    apt-get install libreadline-dev # optional (bup ftp)
+    apt-get install python3-tornado # optional (bup web)
+
+    ```
+   Or, if you can't yet migrate to Python 3 (please try to soon):
 
     ```sh
     apt-get install python2.7-dev python-fuse
-    apt-get install python-pyxattr
+    apt-get install python-pyxattr python-pytest
     apt-get install pkg-config linux-libc-dev libacl1-dev
-    apt-get install acl attr
+    apt-get install gcc make acl attr rsync
     apt-get isntall python-pytest-xdist # optional (parallel tests)
+    apt-get install par2 # optional (error correction)
     apt-get install libreadline-dev # optional (bup ftp)
     apt-get install python-tornado # optional (bup web)
     ```

diff --git a/config/configure b/config/configure
index 407bd4b29df77d50d075ed8ca36435015c11a5d9..6ef05315feaaa0dc349bbf28a1c34d38736672de 100755 (executable)
--- a/config/configure
+++ b/config/configure
@@ -66,13 +66,13 @@ expr "$MAKE_VERSION" '>=' '3.81' || AC_FAIL "ERROR: $MAKE must be >= version 3.8
 AC_SUB bup_make "$MAKE"
 
 bup_python="$(type -p "$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 python3.8 '')"
 test -z "$bup_python" && bup_python="$(bup_find_prog python3.7 '')"
 test -z "$bup_python" && bup_python="$(bup_find_prog python3.6 '')"
 test -z "$bup_python" && bup_python="$(bup_find_prog python3 '')"
+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"