yaourt --needed --noconfirm -S --force upx
go get -u -v github.com/pwaller/goupx
Then you could compress using this command:
$ goupx THE_EXE_FILE
2015/02/23 09:28:36 {Class:ELFCLASS64 Data:ELFDATA2LSB Version:EV_CURRENT OSABI:ELFOSABI_NONE ABIVersion:0 ByteOrder:LittleEndian Type:ET_EXEC Machine:EM_X86_64 Entry:4380896}
2015/02/23 09:28:36 Hemming PT_LOAD section
2015/02/23 09:28:36 File fixed!
Ultimate Packer for eXecutables
Copyright (C) 1996 - 2013
UPX 3.91 Markus Oberhumer, Laszlo Molnar & John Reiser Sep 30th 2013
File size Ratio Format Name
-------------------- ------ ----------- -----------
8746160 -> 2413164 27.59% linux/ElfAMD THE_EXE_FILE
Packed 1 file.