these 2 derivations will be built:
  /nix/store/7w46wh2iimpkpx8qw5ksp2agkcsvms8a-source.drv
  /nix/store/z7m4hqhmf7l870q4scx222im475ch6xa-libviperfx-unstable-2018-01-15.drv
building '/nix/store/rvx3x98m4g6lwvl7mvm0cs42aiwd2z4f-source.drv'
source> 
source> trying https://github.com/vipersaudio/viperfx_core_binary/archive/6f7d0da725affe854f083baf5d90c70e172e4488.tar.gz
source>   % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current
source>                                  Dload  Upload   Total   Spent    Left  Speed
source>   0     0    0     0    0     0      0      0 --:--:-- --:--:-- --:--:--     0
source> 100  382k    0  382k    0     0   510k      0 --:--:-- --:--:-- --:--:--  510k
source> unpacking source archive /nix/var/nix/builds/nix-3098312-3107654954/6f7d0da725affe854f083baf5d90c70e172e4488.tar.gz
building '/nix/store/z7m4hqhmf7l870q4scx222im475ch6xa-libviperfx-unstable-2018-01-15.drv'
libviperfx-unstable-2018-01-15> unpacking sources
libviperfx-unstable-2018-01-15> unpacking source archive /nix/store/0j87chygc99lgh7sm9j4m2fivv8ra2yz-source
libviperfx-unstable-2018-01-15> source root is source
libviperfx-unstable-2018-01-15> patching sources
libviperfx-unstable-2018-01-15> configuring
libviperfx-unstable-2018-01-15> no configure script, doing nothing
libviperfx-unstable-2018-01-15> installing
libviperfx-unstable-2018-01-15> post-installation fixup
libviperfx-unstable-2018-01-15> shrinking RPATHs of ELF executables and libraries in /nix/store/gd8w6f9kzvj7jrhh4fxcqvvrd53lmj4f-libviperfx-unstable-2018-01-15
libviperfx-unstable-2018-01-15> shrinking /nix/store/gd8w6f9kzvj7jrhh4fxcqvvrd53lmj4f-libviperfx-unstable-2018-01-15/lib/libviperfx.so
libviperfx-unstable-2018-01-15> strip is /nix/store/wn31i3dzwahz6ccws8bs1nwyqrpgsvj7-gcc-wrapper-11.3.0/bin/strip
libviperfx-unstable-2018-01-15> stripping (with command strip and flags -S) in  /nix/store/gd8w6f9kzvj7jrhh4fxcqvvrd53lmj4f-libviperfx-unstable-2018-01-15/lib
libviperfx-unstable-2018-01-15> patching script interpreter paths in /nix/store/gd8w6f9kzvj7jrhh4fxcqvvrd53lmj4f-libviperfx-unstable-2018-01-15
libviperfx-unstable-2018-01-15> checking for references to /build/ in /nix/store/gd8w6f9kzvj7jrhh4fxcqvvrd53lmj4f-libviperfx-unstable-2018-01-15...

upload niks3: ok