This error occured during the installation of xserver-meta

--2016-05-10 10:34:55-- http://www.linuxfromscratch.org/patc...xdemos-1.patch
Resolving www.linuxfromscratch.org... 192.155.86.174, 2600:3c01::f03c:91ff:fe70:25e8
Connecting to www.linuxfromscratch.org|192.155.86.174|:80... connected.
HTTP request sent, awaiting response... 404 Not Found
2016-05-10 10:34:55 ERROR 404: Not Found.

Error occured in execution of /var/cache/alps/scripts/mesa.sh
Aborting

It seems the tarball for mesa was not found..

Doing a quick google for this patch: mesa-11.1.1-add_xdemos-1.patch gave the the following location where the patch can be found: linuxfromscratch.org/patches/downloads/mesa/. The patch's download URL is: linuxfromscratch.org/patches/downloads/mesa/mesa-11.1.1-add_xdemos-1.patch which I found by searching through the page for mesa-11.1.1-add_xdemos-1.patch and doing right click -> copy link location in firefox.

Then I simply do:

alps src linuxfromscratch.org/patches/downloads/mesa/mesa-11.1.1-add_xdemos-1.patch

The patch gets downloaded the /var/cache/alps/sources and I can resume the build by doing:

alps install xserver-meta