Not a huge problem, but I bumped into it trying to compile libtorrent 0.12.6 under Slackware 13.
The configure command stopped with the following message:
[... Lots of lines ommitted here ...] checking for OPENSSL... yes checking for STUFF... configure: error: Package requirements (sigc++-2.0) were not met: No package 'sigc++-2.0' found Consider adjusting the PKG_CONFIG_PATH environment variable if you installed software in a non-standard prefix.
So, libtorrent needs libsigc++ to be installed. No big deal, except that libsigc++ is already installed in /usr/local/lib/... What gives?
Well, the configure script helpfully gives you the answer: the PKG_CONFIG_PATH variable needs to be adjusted.
In order to that, we first have to check its actual value:
$ env | grep -i PKG_CONFIG_PATH PKG_CONFIG_PATH=/usr/local/lib64/pkgconfig:/usr/lib64/pkgconfig
Aha! There is the problem. Solving it is as simple as doing this:
$ export PKG_CONFIG_PATH=/usr/local/lib64/pkgconfig:/usr/lib64/pkgconfig:/usr/local/lib/pkgconfig/
Then double-check with the following command:
$ env | grep -i PKG_CONFIG_PATH PKG_CONFIG_PATH=/usr/local/lib64/pkgconfig:/usr/lib64/pkgconfig:/usr/local/lib/pkgconfig/
That's it! From now on, compiling libtorrent is as simple as:
$./configure && make && sudo make install
It is now possible to proceed with the compilation of rtorrent, a very nice console-mode torrent client for the distinguished and discerning gentleman. :-)
The question I am asking myself is: how come libsigc++ is not integrated by default in Slackware 13? Inquiring minds want to know!!