for some reason I'm still keeping track of the release-critical bugs I touch, even though it's a long time since I systematically try to fix them. & since I have the list, I thought I might as well post it here, for the third (& last) time this year:

• #720666 – src:libxml-validate-perl: "libxml-validate-perl: FTBFS: POD coverage test failure"
  don't run POD tests (pkg-perl)
• #810655 – libembperl-perl: "libembperl-perl: postinst fails when libapache2-mod-perl2 is not installed"
  upload backported fix to jessie
• #825011 – libdata-alias-perl: "libdata-alias-perl: FTBFS with Perl 5.24: undefined symbol: LEAVESUB"
  upload new upstream release (pkg-perl)
• #826465 – texlive-latex-recommended: "texlive-latex-recommended: Unescaped left brace in regex is deprecated"
  propose patch
• #851506 – cpanminus: "cpanminus: major parts of upstream sources with compressed white-space"
  take tarball from github (pkg-perl)
• #853490 – src:libdomain-publicsuffix-perl: "libdomain-publicsuffix-perl: ftbfs with GCC-7"
  apply patch from ubuntu (pkg-perl)
• #853499 – src:libopengl-perl: "libopengl-perl: ftbfs with GCC-7"
  new upstream release (pkg-perl)
• #867514 – libsolv: "libsolv: find_package called with invalid argument "2.7.13+""
  propose a patch, later upload to DELAYED/1, then patch included in a maintainer upload
• #869357 – src:libdigest-whirlpool-perl: "libdigest-whirlpool-perl FTBFS on s390x: test failure"
  upload to DELAYED/5
• #869360 – slic3r: "slic3r: missing dependency on perlapi-*"
  upload to DELAYED/5
• #869576 – src:gimp-texturize: "gimp-texturize: Local copy of intltool-* fails with perl 5.26"
  add patch, QA upload
• #869578 – src:gdmap: "gdmap: Local copy of intltool-* fails with perl 5.26"
  provide a patch
• #869579 – src:granule: "granule: Local copy of intltool-* fails with perl 5.26"
  add patch, QA upload
• #869580 – src:teg: "teg: Local copy of intltool-* fails with perl 5.26"
  provide a patch
• #869583 – src:gnome-specimen: "gnome-specimen: Local copy of intltool-* fails with perl 5.26"
  provide a patch
• #869884 – src:chemical-mime-data: "chemical-mime-data: Local copy of intltool-* fails with perl 5.26"
  provide a patch, upload to DELAYED/5 later
• #870213 – src:pajeng: "pajeng FTBFS with perl 5.26"
  provide a patch, uploaded by maintainer
• #870821 – src:esys-particle: "esys-particle FTBFS with perl 5.26"
  propose patch
• #870832 – src:libmath-prime-util-gmp-perl: "libmath-prime-util-gmp-perl FTBFS on big endian: Failed 2/31 test programs. 8/2885 subtests failed."
  upload new upstream release (pkg-perl)
• #871059 – src:fltk1.3: "fltk1.3: FTBFS: Unescaped left brace in regex is illegal here in regex; marked by <-- HERE in m/(\${ <-- HERE _IMPORT_PREFIX}/lib)(?!/x86_64-linux-gnu)/ at debian/fix-fltk-targets-noconfig line 6, <> line 1."
  propose patch
• #871159 – texlive-extra-utils: "pstoedit: FTBFS: Unescaped left brace in regex is illegal here in regex; marked by <-- HERE in m/\\([a-zA-Z]+){([^}]*)}{ <-- HERE ([^}]*)}/ at /usr/bin/latex2man line 1327."
  propose patch
• #871307 – libmimetic0v5: "libmimetic0v5: requires rebuild against GCC 7 and symbols/shlibs bump"
  implement reporter's recipe (thanks!)
• #871335 – src:smlnj: "smlnj: FTBFS: Unescaped left brace in regex is illegal here in regex; marked by <-- HERE in m/~?\\begin{ <-- HERE (small|Bold|Italics|Emph|address|quotation|center|enumerate|itemize|description|boxit|Boxit|abstract|Figure)}/ at mltex2html line 1411, <DOCUMENT> line 1."
  extend existing patch, QA upload
• #871349 – src:ispell-uk: "ispell-uk: FTBFS: The encoding pragma is no longer supported at ../../bin/verb_reverse.pl line 12."
  propose patch
• #871357 – src:packaging-tutorial: "packaging-tutorial: FTBFS: Unescaped left brace in regex is illegal here in regex; marked by <-- HERE in m/\\end{ <-- HERE document}/ at /usr/share/perl5/Locale/Po4a/TransTractor.pm line 643."
  analyze and propose a possible patch
• #871367 – src:fftw: "fftw: FTBFS: Unescaped left brace in regex is deprecated here (and will be fatal in Perl 5.30), passed through in regex; marked by <-- HERE in m/\@(\w+){ <-- HERE ([^\{\}]+)}/ at texi2html line 1771."
  propose patch
• #871818 – src:debian-zh-faq: "debian-zh-faq FTBFS with perl 5.26"
  propose patch
• #872275 – slic3r-prusa: "slic3r-prusa: Loadable library and perl binary mismatch"
  propose patch
• #873697 – src:libtext-bibtex-perl: "libtext-bibtex-perl FTBFS on arm*/ppc64el: t/unlimited.t (Wstat: 11 Tests: 4 Failed: 0)"
  upload new upstream release prepared by smash (pkg-perl)
• #875627 – libauthen-captcha-perl: "libauthen-captcha-perl: Random failure due to bad images"
  upload package with fixed ong prepared by xguimard (pkg-perl)
• #877841 – src:libxml-compile-wsdl11-perl: "libxml-compile-wsdl11-perl: FTBFS Can't locate XML/Compile/Tester.pm in @INC"
  add missing build dependency (pkg-perl)
• #877842 – src:libxml-compile-soap-perl: "libxml-compile-soap-perl: FTBFS: Can't locate Test/Deep.pm in @INC"
  add missing build dependencies (pkg-perl)
• #880777 – src:pdl: "pdl build depends on removed libgd2*-dev provides"
  update build dependency (pkg-perl)
• #880787 – src:libhtml-formatexternal-perl: "libhtml-formatexternal-perl build depends on removed transitional package lynx-cur"
  update build dependency (pkg-perl)
• #880843 – src:libperl-apireference-perl: "libperl-apireference-perl FTBFS with perl 5.26.1"
  change handling of 5.26.1 API (pkg-perl)
• #881058 – gwhois: "gwhois: please switch Depends from lynx-cur to lynx"
  update dependency, upload to DELAYED/15
• #882264 – src:libtemplate-declare-perl: "libtemplate-declare-perl FTBFS with libhtml-lint-perl 2.26+dfsg-1"
  add patch for compatibility with newer HTML::Lint (pkg-perl)
• #883673 – src:libdevice-cdio-perl: "fix build with libcdio 1.0"
  add patch from doko (pkg-perl)
• #885541 – libtest2-suite-perl: "libtest2-suite-perl: file conflicts with libtest2-asyncsubtest-perl and libtest2-workflow-perl"
  add Breaks/Replaces/Provides (pkg-perl)