Groff errors in Manpages

[bernhardschmidt]

Describe the bug Possibly related to OpenVPN/openvpn-build#1156 , lintian (the Debian packaging linter) has a lot of complains about the manpages shipped in the release tarball

W: openvpn: groff-message troff:<standard input>:1142: warning: cannot select font 'C' [usr/share/man/man8/openvpn.8.gz:16]
N:
W: openvpn: groff-message troff:<standard input>:1173: warning: cannot select font 'C' [usr/share/man/man8/openvpn.8.gz:17]
N:
W: openvpn: groff-message troff:<standard input>:1192: warning: cannot select font 'C' [usr/share/man/man8/openvpn.8.gz:18]
N:
W: openvpn: groff-message troff:<standard input>:1248: warning: cannot select font 'C' [usr/share/man/man8/openvpn.8.gz:19]

https://udd.debian.org/lintian/?packages=openvpn

This is not a new thing, 2.6.14 in Debian Stable is also affected.

The errors can be fixed by removing and regenerating the manpages during build. The effective diff between the manpage in the tarball and the freshly generated manpage looks like this (dozens of times each manpage)

@@ -391,11 +377,9 @@
 .INDENT 7.0
 .INDENT 3.5
 .sp
-.nf
-.ft C
+.EX
 keying\-material\-exporter label len
-.ft P
-.fi
+.EE
 .UNINDENT
 .UNINDENT
 .sp

To Reproduce Loading the shipped manpage in groff

$ groff -t -e -mandoc -Tascii doc/openvpn.8 > /dev/null 
troff:doc/openvpn.8:192: warning: cannot select font 'C'
troff:doc/openvpn.8:208: warning: cannot select font 'C'
troff:doc/openvpn.8:223: warning: cannot select font 'C'
troff:doc/openvpn.8:255: warning: cannot select font 'C'
troff:doc/openvpn.8:326: warning: cannot select font 'C'
troff:doc/openvpn.8:360: warning: cannot select font 'C'
troff:doc/openvpn.8:395: warning: cannot select font 'C'
[...]

Expected behavior No groff warnings

Version information (please complete the following information): 2.7-rc3 tarball

Additional context Add any other context about the problem here.