[Pgbuildfarm-members] Running gdb on core files

run_build.pl calls gdb on detected cores as:

gdb -ex bt --batch $bindir/postgres $core

The -ex option was added in gdb 6.4, released in 2005. One might assume
that was long enough ago, but, alas, FreeBSD's system gdb is still
version 6.1.1 (for GPLv3 reasons apparently, and there is a 7.6 in
ports). Interestingly enough, gdb 6.1.1 accepts the current command line
without complaint -- but also without result.

The attached patch replaces -ex with -x and writes a command file for it
to read.

Alternatively, run_build.pl could check the gdb version, and if it
encounters anything before 6.4, just print a notice that there is no
backtrace.

--
Christian