I want to build libreoffice-9999-r1 on an ARM architecture based platform (Toshiba AC100) with 512MB RAM. During pre-merge checks for app-office/libreoffice-9999-r1 I got the message * There is NOT at lease 1 gibibytes RAM * Space constrains set in the ebuild were not met! and emerge stops. I think there must be a way to build this package even if it has less RAM. The compiled binary may be slow, but there should be the possibility to build the package.
I believe the reason it needs so much ram is because some of the LO source files are huge and GCC needs that much ram to compile them. Linking the final binaries together might also take a lot of ram. You can always try "I_KNOW_WHAT_I_AM_DOING=yes emerge libreoffice" to ignore the check and see what happens. You'll at least want to check that your system is compiled with CFLAGS=-Os and libreoffice is compiled with MAKEOPTS=-j1. Have the bare minimum programs running (no GUI desktop). Not sure what else can help, short of swapping ld with gold and/or gcc with clang. If you've got enough swap space, compilation will probably not so mauch fail as take forever to complete.
1) It has no arm keywords. 2) The 1 GB is checked on amd64 one thread build. So the constrains are set to be some sane minimal, if you trust you can build it on your machine you can always disable the check with the I_KNOW_WHAT_I_AM_DOING variable. This is something that we won't fix. For sake of few I won't break build for many.