Dear Maintainer,
I encountered a similar error with libtgowt. 😥️
$ wget https://snapshot.debian.org/archive/debian/20210731T211848Z/pool/main/libt/libtgowt/libtgowt_0%7Egit20210627.91d836d%2Bdfsg.orig.tar.xz
$ sha256sum *.orig.tar.xz
7def3e544b250339d55e4ecf66f64c79aea208c863a3ba94f2fddedbf82768de libtgowt_0~git20210627.91d836d+dfsg.orig.tar.xz
$ git clone git@salsa.debian.org:debian/libtgowt.git
$ cd libtgowt
$ pristine-tar --verbose --debug commit ../libtgowt_0~git20210627.91d836d+dfsg.orig.tar.xz upstream/0_git20210627.91d836d+dfsg
pristine-tar: git archive --format=tar e03d74eda2741fd5e2bdf6010f6e9281154b2182 | (cd '/tmp/pristine-tar.3iEmF49ajq' && tar x)
pristine-tar: set subdir to libtgowt-0~git20210627.91d836d
pristine-tar: subdir is libtgowt-0~git20210627.91d836d
pristine-tar: mkdir /tmp/pristine-tar.YDSJ2ztiV2/workdir
pristine-tar: mv /tmp/pristine-tar.3iEmF49ajq /tmp/pristine-tar.YDSJ2ztiV2/workdir/libtgowt-0~git20210627.91d836d
pristine-tar: libtgowt-0~git20210627.91d836d/.gitignore is listed in the manifest but may not be present in the source directory
pristine-tar: creating missing libtgowt-0~git20210627.91d836d/.gitignore
pristine-tar: libtgowt-0~git20210627.91d836d/.gitmodules is listed in the manifest but may not be present in the source directory
pristine-tar: creating missing libtgowt-0~git20210627.91d836d/.gitmodules
pristine-tar: libtgowt-0~git20210627.91d836d/src/third_party/libvpx/source/libvpx/.gitattributes is listed in the manifest but may not be present in the source directory
pristine-tar: creating missing libtgowt-0~git20210627.91d836d/src/third_party/libvpx/source/libvpx/.gitattributes
pristine-tar: libtgowt-0~git20210627.91d836d/src/third_party/libvpx/source/libvpx/.gitignore is listed in the manifest but may not be present in the source directory
pristine-tar: creating missing libtgowt-0~git20210627.91d836d/src/third_party/libvpx/source/libvpx/.gitignore
pristine-tar: libtgowt-0~git20210627.91d836d/src/third_party/libyuv/.gitignore is listed in the manifest but may not be present in the source directory
pristine-tar: creating missing libtgowt-0~git20210627.91d836d/src/third_party/libyuv/.gitignore
pristine-tar: libtgowt-0~git20210627.91d836d/src/third_party/openh264/src/.gitignore is listed in the manifest but may not be present in the source directory
pristine-tar: creating missing libtgowt-0~git20210627.91d836d/src/third_party/openh264/src/.gitignore
pristine-tar: libtgowt-0~git20210627.91d836d/src/third_party/openh264/src/autotest/performanceTest/.gitignore is listed in the manifest but may not be present in the source directory
pristine-tar: creating missing libtgowt-0~git20210627.91d836d/src/third_party/openh264/src/autotest/performanceTest/.gitignore
pristine-tar: libtgowt-0~git20210627.91d836d/src/third_party/openh264/src/autotest/unitTest/.gitignore is listed in the manifest but may not be present in the source directory
pristine-tar: creating missing libtgowt-0~git20210627.91d836d/src/third_party/openh264/src/autotest/unitTest/.gitignore
pristine-tar: libtgowt-0~git20210627.91d836d/src/third_party/openh264/src/codec/build/android/.gitignore is listed in the manifest but may not be present in the source directory
pristine-tar: creating missing libtgowt-0~git20210627.91d836d/src/third_party/openh264/src/codec/build/android/.gitignore
pristine-tar: libtgowt-0~git20210627.91d836d/src/third_party/openh264/src/codec/build/iOS/.gitignore is listed in the manifest but may not be present in the source directory
pristine-tar: creating missing libtgowt-0~git20210627.91d836d/src/third_party/openh264/src/codec/build/iOS/.gitignore
pristine-tar: libtgowt-0~git20210627.91d836d/src/third_party/openh264/src/codec/build/win32/.gitignore is listed in the manifest but may not be present in the source directory
pristine-tar: creating missing libtgowt-0~git20210627.91d836d/src/third_party/openh264/src/codec/build/win32/.gitignore
pristine-tar: libtgowt-0~git20210627.91d836d/src/third_party/openh264/src/codec/build/windowsphone/.gitignore is listed in the manifest but may not be present in the source directory
pristine-tar: creating missing libtgowt-0~git20210627.91d836d/src/third_party/openh264/src/codec/build/windowsphone/.gitignore
pristine-tar: libtgowt-0~git20210627.91d836d/src/third_party/openh264/src/codec/common/inc/.gitignore is listed in the manifest but may not be present in the source directory
pristine-tar: creating missing libtgowt-0~git20210627.91d836d/src/third_party/openh264/src/codec/common/inc/.gitignore
pristine-tar: libtgowt-0~git20210627.91d836d/src/third_party/openh264/src/codec/processing/build/win32/.gitignore is listed in the manifest but may not be present in the source directory
pristine-tar: creating missing libtgowt-0~git20210627.91d836d/src/third_party/openh264/src/codec/processing/build/win32/.gitignore
pristine-tar: libtgowt-0~git20210627.91d836d/src/third_party/openh264/src/test/build/android/.gitignore is listed in the manifest but may not be present in the source directory
pristine-tar: creating missing libtgowt-0~git20210627.91d836d/src/third_party/openh264/src/test/build/android/.gitignore
pristine-tar: libtgowt-0~git20210627.91d836d/src/third_party/openh264/src/test/build/win32/.gitignore is listed in the manifest but may not be present in the source directory
pristine-tar: creating missing libtgowt-0~git20210627.91d836d/src/third_party/openh264/src/test/build/win32/.gitignore
pristine-tar: libtgowt-0~git20210627.91d836d/src/third_party/openh264/src/test/build/windowsphone/.gitignore is listed in the manifest but may not be present in the source directory
pristine-tar: creating missing libtgowt-0~git20210627.91d836d/src/third_party/openh264/src/test/build/windowsphone/.gitignore
pristine-tar: libtgowt-0~git20210627.91d836d/src/third_party/openh264/src/test/encoder_binary_comparison/.gitignore is listed in the manifest but may not be present in the source directory
pristine-tar: creating missing libtgowt-0~git20210627.91d836d/src/third_party/openh264/src/test/encoder_binary_comparison/.gitignore
pristine-tar: libtgowt-0~git20210627.91d836d/src/third_party/usrsctp/usrsctplib/.gitignore is listed in the manifest but may not be present in the source directory
pristine-tar: creating missing libtgowt-0~git20210627.91d836d/src/third_party/usrsctp/usrsctplib/.gitignore
pristine-tar: doing full tree sweep to catch missing files
pristine-tar: tar cf /tmp/pristine-tar.YDSJ2ztiV2/recreatetarball --owner 0 --group 0 --numeric-owner -C /tmp/pristine-tar.YDSJ2ztiV2/workdir --no-recursion --mode 0644 --verbatim-files-from --files-from /tmp/pristine-tar.YDSJ2ztiV2/manifest
pristine-tar: pristine-xz -v -d --no-keep gendelta ../libtgowt_0~git20210627.91d836d+dfsg.orig.tar.xz /tmp/pristine-tar.YHnBJuQEvm/wrapper
pristine-xz: pixz -d < ../libtgowt_0~git20210627.91d836d+dfsg.orig.tar.xz > /tmp/pristine-tar.52SYvnzUZx/test
pristine-xz: xz --check=crc64 -z -6 < /tmp/pristine-tar.52SYvnzUZx/test > /tmp/pristine-tar.52SYvnzUZx/test.xz
pristine-xz: xz --check=crc64 -z -6e < /tmp/pristine-tar.52SYvnzUZx/test > /tmp/pristine-tar.52SYvnzUZx/test.xz
pristine-xz: xz --check=crc64 -z -5 < /tmp/pristine-tar.52SYvnzUZx/test > /tmp/pristine-tar.52SYvnzUZx/test.xz
pristine-xz: xz --check=crc64 -z -5e < /tmp/pristine-tar.52SYvnzUZx/test > /tmp/pristine-tar.52SYvnzUZx/test.xz
jpristine-xz failed to reproduce build of ../libtgowt_0~git20210627.91d836d+dfsg.orig.tar.xz
(Please file a bug report.)
pristine-tar: failed to generate delta