these derivations will be built:
  /nix/store/s1ka0cr7b04xwbkd7hfw82dcq22rli2x-custom-dwm-0.drv
building path(s) ‘/nix/store/ssg5arh2fb306dhw2c6m4rjqa343i7n1-custom-dwm-0’
unpacking sources
unpacking source archive /nix/store/qkx4b7mns83wj1id4gfig2cdncxmfpf4-0.tar.gz
source root is custom-dwm-0
setting SOURCE_DATE_EPOCH to timestamp 1489514710 of file custom-dwm-0/dwm.c
patching sources
configuring
no configure script, doing nothing
building
dwm build options:
CFLAGS   = -std=c99 -pedantic -Wall -Os -I. -I/usr/include -I/usr/X11R6/include -DVERSION="6.0" -DXINERAMA
LDFLAGS  = -s -L/usr/lib -lc -L/usr/X11R6/lib -lX11 -L/usr/X11R6/lib -lXinerama
CC       = cc
CC dwm.c
dwm.c: In function 'keypress':
dwm.c:1088:2: warning: 'XKeycodeToKeysym' is deprecated [-Wdeprecated-declarations]
  keysym = XKeycodeToKeysym(dpy, (KeyCode)ev->keycode, 0);
  ^
In file included from dwm.c:37:0:
/nix/store/5dpmbnk0cls2nszj9cfvyndam5bsfrlf-libX11-1.6.4-dev/include/X11/Xlib.h:1687:15: note: declared here
 extern KeySym XKeycodeToKeysym(
               ^
dwm.c: At top level:
dwm.c:1194:1: warning: 'monocle' defined but not used [-Wunused-function]
 monocle(Monitor *m) {
 ^
CC -o dwm
/nix/store/ssg5arh2fb306dhw2c6m4rjqa343i7n1-custom-dwm-0
installing
install flags: install
dwm build options:
CFLAGS   = -std=c99 -pedantic -Wall -Os -I. -I/usr/include -I/usr/X11R6/include -DVERSION="6.0" -DXINERAMA
LDFLAGS  = -s -L/usr/lib -lc -L/usr/X11R6/lib -lX11 -L/usr/X11R6/lib -lXinerama
CC       = cc
installing executable file to /usr/local/bin
cp: cannot create regular file '/usr/local/bin/dwm': Permission denied
make: *** [Makefile:47: install] Error 1
builder for ‘/nix/store/s1ka0cr7b04xwbkd7hfw82dcq22rli2x-custom-dwm-0.drv’ failed with exit code 2
error: build of ‘/nix/store/s1ka0cr7b04xwbkd7hfw82dcq22rli2x-custom-dwm-0.drv’ failed