When compiling wallet on Ubuntu 12.04 error
g++ -c -O2 -pthread -Wall -Wextra -Wno-ignored-qualifiers -Wformat -Wformat-security -Wno-unused-parameter -g -DBOOST_SPIRIT_THREADSAFE -I/root/~build/wallet/ParkByte/src -I/root/~build/wallet/ParkByte/src/obj -I/root/~build/wallet/ParkByte/src/leveldb/include -I/root/~build/wallet/ParkByte/src/leveldb/helpers -DHAVE_BUILD_INFO -fno-stack-protector -fstack-protector-all -Wstack-protector -D_FORTIFY_SOURCE=2 -MMD -MF obj/zerocoin/Accumulator.d -o obj/zerocoin/Accumulator.o zerocoin/Accumulator.cpp
zerocoin/Accumulator.cpp:106:1: fatal error: opening dependency file obj/zerocoin/Accumulator.d: No such file or directory
compilation terminated.
make: *** [obj/zerocoin/Accumulator.o] Error 1
Who knows? How to fix?