[Syslog-ng-maintainers] Bug#949847: syslog-ng FTBFS: configure: error: syslog-ng requires bison 3.4 or later

[Andreas Henriksson]

Hi,

On Sat, Jan 25, 2020 at 09:25:45PM +0100, Helmut Grohne wrote:
> Source: syslog-ng
> Version: 3.25.1-1
> Severity: serious
> Tags: ftbfs
> 
> syslog-ng fails to build from source in unstable. A build log contains:
> 
> | configure: error: syslog-ng requires bison 3.4 or later (traditional yacc is not enough). Your source tree seems to be from git, which doesn't have lib/cfg-grammar.c. Please install bison or use a distribution tarball.
> 
> This seems a bit strange since it earlier finds:
> 
> | checking for bison... bison -y
[...]

It seems the sed expression in configure.ac doesn't do anything at:
https://sources.debian.org/src/syslog-ng/3.25.1-1/configure.ac/#L425

This means bison_version will contain eg.:

$ bison --version | head -n 1 
bison (GNU Bison) 3.3.2

And since 'cut -d .' is used, then bison_version_major becomes:
bison (GNU Bison) 3

And since it's expected to be an integer it won't evaluate
to -ge 3.

Personally I'm not familiar with exprission like '@<:@^0-9.@:>@*'
and where they are documented. Using codesearch.debian.net[1] they
show up in many places not only for sed, but also passed to grep,
tr, etc. If someone knows where these expressions are documented
please tell me. Maybe the problem is in some underlying component
rather than syslog-ng.

Regards,
Andreas Henriksson

[1]: https://codesearch.debian.net/search?q=%2F%40%3C%3A&literal=1&perpkg=1