Bug#876587: gnutls28 FTBFS with gtk-doc-tools 1.26: gtkdoc-mktmpl is no longer available

[Adrian Bunk]

Source: gnutls28
Version: 3.5.15-2
Severity: serious

https://tests.reproducible-builds.org/debian/rb-pkg/unstable/amd64/gnutls28.html

...
Making all in reference
make[6]: Entering directory '/build/1st/gnutls28-3.5.15/doc/reference'
  DOC   Scanning header files
  DOC   Rebuilding template files
/bin/bash: gtkdoc-mktmpl: command not found
Makefile:1671: recipe for target 'tmpl-build.stamp' failed
make[6]: *** [tmpl-build.stamp] Error 127