Etc.sysconfig contains "$(DESTDIR)" when ./configure is called with --sysconfdir=
When the Ruby source files are configured for compilation with ./configure and the --sysconfdir= parameter is specified, the "ext/etc/extconf.h" file is generated with a SYSCONFDIR variable that contains "$(DESTDIR)" literally, not expanded. For example:
$ ./configure --prefix=/usr --sysconfdir=/etc
$ grep SYSCONFDIR ext/etc/extconf.h
#define SYSCONFDIR "$(DESTDIR)/etc"
This variable was introduced in r27667 and seems only used in "lib/rubygems/config_file.rb". Why not use Config::CONFIG['sysconfdir'] there (rbconfig is already required by rubygems)?
Note: this was verified on Linux RHEL 5 with ruby-1.9.2-p0.tar.bz2.