编译GDB时出现以下错误。
../readline/libreadline.a ../opcodes/libopcodes.a ../bfd/libbfd.a ../libiberty/libiberty.a ../libdecnumber/libdecnumber.a -ldl -ltermcap -lz -lm -L/usr/lib/python2.7/config -lpthread -ldl -lutil -lm -lpython2.7 -Xlinker -export-dynamic -Wl,-O1 -Wl,-Bsymbolic-functions -lexpat ../libiberty/libiberty.a build-gnulib/import/libgnu.a
python.o: In function `gdbpy_target_charset':
python.c:(.text+0x7b5): undefined reference to `PyUnicodeUCS2_Decode'
python.o: In function `gdbpy_target_wide_charset':
python.c:(.text+0x820): undefined reference to `PyUnicodeUCS2_Decode'
py-cmd.o: In function `cmdpy_function':
py-cmd.c:(.text+0x39b): undefined reference to `PyUnicodeUCS2_Decode'
py-cmd.o: In function `cmdpy_completer':
py-cmd.c:(.text+0x74c): undefined reference to `PyUnicodeUCS2_Decode'
py-cmd.c:(.text+0x7c0): undefined reference to `PyUnicodeUCS2_Decode'
py-frame.o:py-frame.c:(.text+0x29b): more undefined references to `PyUnicodeUCS2_Decode' follow
py-utils.o: In function `python_string_to_unicode':
py-utils.c:(.text+0xe1): undefined reference to `PyUnicodeUCS2_FromEncodedObject'
py-utils.o: In function `unicode_to_encoded_string':
py-utils.c:(.text+0x13c): undefined reference to `PyUnicodeUCS2_AsEncodedString'
py-utils.o: In function `unicode_to_encoded_python_string':
py-utils.c:(.text+0x1c7): undefined reference to `PyUnicodeUCS2_AsEncodedString'
py-utils.o: In function `target_string_to_unicode':
py-utils.c:(.text+0x409): undefined reference to `PyUnicodeUCS2_Decode'
py-value.o: In function `valpy_string':
py-value.c:(.text+0xb8b): undefined reference to `PyUnicodeUCS2_Decode'
py-value.o: In function `valpy_str':
py-value.c:(.text+0x141b): undefined reference to `PyUnicodeUCS2_Decode'
collect2: ld returned 1 exit status
make[2]: *** [gdb] Error 1
make[2]: Leaving directory
它可能是什么原因？