[Pkg-phototools-devel] Bug#1013909: pngtools: Package fails to build without network access

[Michael Schaller]

Source: pngtools
Version: 0.5~git20220314.1ccca3a-1
Severity: serious
Tags: ftbfs
Justification: 4
X-Debbugs-Cc: misch at google.com

Dear Maintainer,

The pngtools source package currently fails to auto-build:
https://tests.reproducible-builds.org/debian/rbuild/unstable/amd64/pngtools_0.5~git20220314.1ccca3a-1.rbuild.log.gz

Relevant snippet from the build log:
...
Working on: /build/1st/pngtools-0.5~git20220314.1ccca3a/man/pngchunkdesc.sgml
onsgmls:/build/1st/pngtools-0.5~git20220314.1ccca3a/man/pnginfo.sgml:16:59:E: could not resolve host "www.oasis-open.org" (try again later)
...

The reason for the build failure is that `onsgmls` (balled by `docbook2man`) does a SGML validation against the DTD specified in the SGML file.
The remote DTD file in question is http://www.oasis-open.org/docbook/sgml/4.4/docbook.dtd.
On autobuild systems however there is no network connection during the build and so the build fails with `could not resolve host "www.oasis-open.org"`.

You can easily reproduce this build issue (with a slightly different error message) by adding `127.0.0.1 www.oasis-open.org` to your `/etc/hosts`.

To fix this issue you need to make the DTD available locally. For example see the `openjade` package, particularly `/etc/sgml/openjade.cat` and `/usr/share/sgml/OpenJade/`. 

Best,

Michael Schaller