[xmonad] xmobar-0.9.1 cannot compile

hi, this is the output: Configuring xmobar-0.9... Warning: This package indirectly depends on multiple versions of the same package. This is highly likely to cause a compile failure. package X11-xft-0.3 requires utf8-string-0.3.3 package xmobar-0.9 requires utf8-string-0.3.4 Preprocessing executables for xmobar-0.9... Building xmobar-0.9... Linking dist/build/xmobar/xmobar ... /usr/bin/ld: cannot find -lHSutf8-string-0.3.3 different version of utf8-string are required. how to fix it? regards lars