This fail https://ci.debian.net/packages/g/gscan2pdf/testing/amd64/70491010/

t/113_save_pdf_with_downsample.t            (Wstat: 256 (exited 1) Tests: 1
Failed: 0)

(113_save_pdf_with_downsample.t:13297): dbind-WARNING **: 21:23:19.572: AT-SPI:
Error retrieving accessibility bus address:
org.freedesktop.DBus.Error.ServiceUnknown: The name org.a11y.Bus was not
provided by any .service files
227s Your system does not have Image::PNG::Libpng installed, so some
227s PNG functions may not run correctly.
227s ok 1 - downsampled PDF smaller than original
227s identify: unable to open image 'x-000.pbm': No such file or directory @
error/blob.c/OpenBlob/3711.
227s "identify" unexpectedly returned exit value 1 at
t/113_save_pdf_with_downsample.t line 66.
227s # Looks like your test exited with 1 just after 1.
227s Perl exited with active threads:
227s    1 running and unjoined
227s    0 finished and unjoined
227s    0 running and detached
227s Dubious, test returned 1 (wstat 256, 0x100)