MANIFEST.in

 include COPYING
 include README.rst
 include CONTRIBUTING.md
+include extras_require.json
 include pyproject.toml
 graft tests

debian/changelog

-diffoscope (233) UNRELEASED; urgency=medium
+diffoscope (233) unstable; urgency=medium
 
-  * WIP (generated upon release).
+  [ FC Stegerman ]
+  * Split packaging metadata into an extras_require.json file instead of using
+    the pep517 and the pip modules directly. This was causing build failures if
+    not using a virtualenv and/or building without internet access.
+    (Closes: #1029066, reproducible-builds/diffoscope#325)
+
+  [ Vagrant Cascadian ]
+  * Add an external tool reference for GNU Guix (lzip).
+  * Drop an external tool reference for GNU Guix (pedump).
+
+  [ Chris Lamb ]
+  * Split inline Python code in shell script to generate test dependencies to a
+    separate Python script.
+  * No need for "from __future__ import print_function" import in setup.py
+    anymore.
+  * Comment and tidy the new extras_require.json handling.
 
- -- Chris Lamb <lamby@debian.org>  Fri, 13 Jan 2023 07:06:45 +0000
+ -- Chris Lamb <lamby@debian.org>  Fri, 20 Jan 2023 08:56:22 -0800
 
 diffoscope (232) unstable; urgency=medium
 

debian/control

@@ -73,8 +73,6 @@ Build-Depends:
  python3-libarchive-c,
  python3-magic,
  python3-pdfminer <!nocheck>,
- python3-pep517,
- python3-pip,
  python3-progressbar <!nocheck>,
  python3-pypdf2 <!nocheck>,
  python3-pytest <!nocheck>,

debian/tests/generate-recommends.py

 #!/usr/bin/env python3
 
-from pep517 import meta
+import json
 
-from pip._internal.req.constructors import install_req_from_req_string
+# Load extras_require dict from external JSON file. This allows it to be easily
+# shared by the main setup.py script.
+with open("extras_require.json") as f:
+    extras_require = json.load(f)
 
-dist = meta.load(".")
-
-xs = set(
-    f"python3-{install_req_from_req_string(x).name}"
-    for x in dist.requires
-    if install_req_from_req_string(x).markers
-)
+xs = set(f"python3-{x}" for reqs in extras_require.values() for x in reqs)
 
 print(", ".join(sorted(xs)))

diffoscope/__init__.py

@@ -17,4 +17,4 @@
 # You should have received a copy of the GNU General Public License
 # along with diffoscope.  If not, see <https://www.gnu.org/licenses/>.
 
-VERSION = "232"
+VERSION = "233"

extras_require.json

+{
+  "distro_detection": [
+    "distro"
+  ],
+  "cmdline": [
+    "argcomplete",
+    "progressbar"
+  ],
+  "comparators": [
+    "androguard",
+    "binwalk",
+    "defusedxml",
+    "guestfs",
+    "jsondiff",
+    "python-debian",
+    "pypdf",
+    "pyxattr",
+    "rpm-python",
+    "tlsh"
+  ]
+}

setup.py

 #!/usr/bin/env python3
 
-from __future__ import print_function
-
-import sys
 import diffoscope
+import json
+import sys
 
 from setuptools import setup, find_packages
 from setuptools.command.test import test as TestCommand
@@ -34,6 +33,11 @@ class PyTest(TestCommand):
         sys.exit(errno)
 
 
+# Load extras_require dict from external JSON file. This allows it to be easily
+# shared by the debian/tests/generate-recommends.py script.
+with open("extras_require.json") as f:
+    extras_require = json.load(f)
+
 setup(
     name="diffoscope",
     version=diffoscope.VERSION,
@@ -56,22 +60,7 @@ setup(
         "python-magic",
         "libarchive-c",
     ],
-    extras_require={
-        "distro_detection": ["distro"],
-        "cmdline": ["argcomplete", "progressbar"],
-        "comparators": [
-            "androguard",
-            "binwalk",
-            "defusedxml",
-            "guestfs",
-            "jsondiff",
-            "python-debian",
-            "pypdf",
-            "pyxattr",
-            "rpm-python",
-            "tlsh",
-        ],
-    },
+    extras_require=extras_require,
     python_requires=">=3.7",
     classifiers=[
         "Development Status :: 3 - Alpha",