Attaching here a debdiff with the patch.
Alternatively, there is release 2.1.5 (and up to 2.2.4) available upstream which includes the fix.
diff -Nru duplicity-2.1.4/debian/changelog duplicity-2.1.4/debian/changelog --- duplicity-2.1.4/debian/changelog 2024-09-24 11:20:12.000000000 +0200 +++ duplicity-2.1.4/debian/changelog 2024-12-17 17:16:15.000000000 +0100 @@ -1,3 +1,11 @@ +duplicity (2.1.4-5) unstable; urgency=medium + + [ Jeremy Bícha ] + * Cherry-pick patch to drop unnecessary Depends: python3-setuptools-scm + (Closes: #1090373). + + -- Alessandro Astone <alessandro.ast...@canonical.com> Tue, 17 Dec 2024 17:16:15 +0100 + duplicity (2.1.4-4) unstable; urgency=medium * updated watch file (closes: #1079706) diff -Nru duplicity-2.1.4/debian/patches/08-scm-depends duplicity-2.1.4/debian/patches/08-scm-depends --- duplicity-2.1.4/debian/patches/08-scm-depends 1970-01-01 01:00:00.000000000 +0100 +++ duplicity-2.1.4/debian/patches/08-scm-depends 2024-12-17 17:15:55.000000000 +0100 @@ -0,0 +1,22 @@ +From: Gwyn Ciesla <gw...@protonmail.com> +Date: Mon, 4 Dec 2023 21:03:28 +0000 +Subject: chg:pkg: setuptools_scm not needed at runtime. + +Origin: 2.1.5 +--- + setup.py | 2 ++ + 1 file changed, 2 insertions(+) + +diff --git a/setup.py b/setup.py +index 275e53f..5c6ea52 100755 +--- a/setup.py ++++ b/setup.py +@@ -348,6 +348,8 @@ setup( + include_package_data=True, + install_requires=[ + "fasteners", ++ ], ++ setup_requires=[ + "setuptools_scm", + ], + tests_require=[ diff -Nru duplicity-2.1.4/debian/patches/series duplicity-2.1.4/debian/patches/series --- duplicity-2.1.4/debian/patches/series 2023-12-20 22:46:45.000000000 +0100 +++ duplicity-2.1.4/debian/patches/series 2024-12-17 17:15:55.000000000 +0100 @@ -4,3 +4,4 @@ 05-testsuite 06-noenv 07-giobackend +08-scm-depends
