running build_ext
building 'igraph.core' extension
creating build/temp.linux-x86_64-2.6
creating build/temp.linux-x86_64-2.6/src
gcc -pthread -fno-strict-aliasing -DNDEBUG -g -fwrapv -O2 -Wall -Wstrict-prototypes -fPIC -I/usr/include -I/usr/local/include -I../../include -I/usr/local/include -I/usr/include -I/usr/include/python2.6 -c src/error.c -o build/temp.linux-x86_64-2.6/src/error.o
src/error.c:25:27: error: igraph/igraph.h: No such file or directory
src/error.c: In function ‘igraphmodule_igraph_error_hook’:
src/error.c:75: error: ‘IGRAPH_UNIMPLEMENTED’ undeclared (first use in this function)
src/error.c:75: error: (Each undeclared identifier is reported only once
src/error.c:75: error: for each function it appears in.)
src/error.c:78: error: ‘IGRAPH_ENOMEM’ undeclared (first use in this function)
src/error.c:82: warning: implicit declaration of function ‘igraph_strerror’
src/error.c:82: warning: format ‘%s’ expects type ‘char *’, but argument 6 has type ‘int’
src/error.c:83: warning: implicit declaration of function ‘IGRAPH_FINALLY_FREE’
error: command 'gcc' failed with exit status 1