Release 2.1.1: Defensively pin pip-accel requirement

I intend to revive pip-accel based on the latest pip release, offering a
minimal conceptual subset of previous functionality of pip-accel, just
enough for py2deb to use.

However this will surely take some time to flesh out - possibly multiple
releases of both projects. I'm not even sure yet what will be involved
in getting pip-accel and py2deb running on the latest version of pip (I
can however already tell that large architectural changes will be
required in pip-accel and consequently also py2deb).

In the mean time I don't want any users (including my employer) run into
breakage caused by this endeavor. Alpha / beta releases on PyPI should
be able to avoid this problem, however I've never published those
myself, so I'm opting for "defense in depth" 😇.

See also this recent discussion:
#18

CHANGELOG.rst

@@ -11,6 +11,28 @@ to `semantic versioning`_.
 .. _Keep a Changelog: http://keepachangelog.com/
 .. _semantic versioning: http://semver.org/
 
+`Release 2.1.1`_ (2020-05-26)
+-----------------------------
+
+**Defensively pin pip-accel requirement.**
+
+I intend to revive pip-accel_ based on the latest pip_ release, offering a
+minimal conceptual subset of previous functionality of pip-accel_, just enough
+for py2deb to use for downloading and unpacking distribution archives.
+
+However this will surely take some time to flesh out - possibly multiple
+releases of both projects. I'm not even sure yet what will be involved in
+getting pip-accel and py2deb running on the latest version of pip (I can
+however already tell that large architectural changes will be required in
+pip-accel and consequently also py2deb).
+
+In the mean time I don't want any users (including my employer) run into
+breakage caused by this endeavor. Alpha / beta releases on PyPI should be able
+to avoid this problem, however I've never published those myself, so I'm opting
+for "defense in depth" 😇.
+
+.. _Release 2.1.1: https://github.com/paylogic/py2deb/compare/2.1...2.1.1
+
 `Release 2.1`_ (2018-12-16)
 ---------------------------
 
@@ -252,7 +274,7 @@ Update usage instructions in readme (and automate the process for the future).
 `Release 0.21`_ (2015-04-04)
 ----------------------------
 
-Upgraded dependencies: pip-accel 0.25 and pip 6.
+Upgraded dependencies: pip-accel_ 0.25 and pip_ 6.
 
 .. _Release 0.21: https://github.com/paylogic/py2deb/compare/0.20.11...0.21
 
@@ -1058,7 +1080,7 @@ Process required packages in alphabetical sort order.
 `Release 0.8.1`_ (2013-08-13)
 -----------------------------
 
-- Implement control overrides for pip-accel backend (also: refactor configuration handling).
+- Implement control overrides for pip-accel_ backend (also: refactor configuration handling).
 - Make it possible to override individual Debian package names.
 - Backends shouldn't know about "replacements".
 

py2deb/__init__.py

@@ -3,7 +3,7 @@
 # Authors:
 #  - Arjan Verwer
 #  - Peter Odding <[email protected]>
-# Last Change: December 16, 2018
+# Last Change: May 26, 2020
 # URL: https://py2deb.readthedocs.io
 
 """
@@ -15,4 +15,4 @@
 """
 
 # Semi-standard module versioning.
-__version__ = '2.1'
+__version__ = '2.1.1'

requirements.txt

@@ -4,7 +4,7 @@ coloredlogs >= 0.5
 deb-pkg-tools >= 5.2
 executor >= 21.0
 humanfriendly >= 4.4
-pip-accel >= 0.25
+pip-accel >= 0.25, <= 0.43
 pkginfo >= 1.1
 property-manager >= 2.3.1
 six >= 1.6.1