Each time I build julia with make -j4 it takes excruciatingly long..
Is there any solution to make this faster, each compile takes an hour or so..
several things can help here. CCache will reduce the amount of recompilation necessary. configuring swap appropriately (e.g. zswap for compressed memory) will also help. lastly, if you have get little ram you may want to not pass -j as it does increase the memory used
The biggest issue is probably running make -j4 with limited RAM. More parallel jobs can actually slow things down if the system starts swapping. Try lowering the job count, use ccache for repeated builds, and make sure swap/zswap is configured properly. More RAM will also make a noticeable difference.