Thunar doesn't compile due to missing function declarations in tdb.c: gcc -DHAVE_CONFIG_H -I. -I.. -I.. -D_FORTIFY_SOURCE=2 -DG_ENABLE_DEBUG -g -O2 -DXFCE_DISABLE_DEPRECATED -Wall -Wextra -Wno-missing-field-initializers -Wno-unused-parameter -Wold-style-definition -Wdeclaration-after-statement -Wmissing-declarations -Wredundant-decls -Wmissing-noreturn -Wshadow -Wpointer-arith -Wcast-align -Wformat-security -Winit-self -Wmissing-include-dirs -Wundef -Wmissing-format-attribute -Wnested-externs -fstack-protector -O0 -g3 -Werror -MT tdb.lo -MD -MP -MF .deps/tdb.Tpo -c tdb.c -fPIC -DPIC -o .libs/tdb.o cc1: warnings being treated as errors tdb.c: In function 'tdb_write': tdb.c:398: error: implicit declaration of function 'pwrite' tdb.c:398: error: nested extern declaration of 'pwrite' tdb.c: In function 'tdb_read': tdb.c:421: error: implicit declaration of function 'pread' tdb.c:421: error: nested extern declaration of 'pread' make[2]: *** [tdb.lo] Error 1 make[2]: Leaving directory `/home/jens/devel/xfce4/thunar/tdb' make[1]: *** [all-recursive] Error 1 make[1]: Leaving directory `/home/jens/devel/xfce4/thunar' make: *** [all] Error 2 jens@neptun:~/devel/xfce4/thunar$