I got the same problem.
gmake all-recursive
gmake[1]: Entering directory `/opt/aMule-2.1.2'
Making all in m4
gmake[2]: Entering directory `/opt/aMule-2.1.2/m4'
gmake[2]: Nothing to be done for `all'.
gmake[2]: Leaving directory `/opt/aMule-2.1.2/m4'
Making all in docs
gmake[2]: Entering directory `/opt/aMule-2.1.2/docs'
Making all in man
gmake[3]: Entering directory `/opt/aMule-2.1.2/docs/man'
gmake[3]: Nothing to be done for `all'.
gmake[3]: Leaving directory `/opt/aMule-2.1.2/docs/man'
gmake[3]: Entering directory `/opt/aMule-2.1.2/docs'
gmake[3]: Nothing to be done for `all-am'.
gmake[3]: Leaving directory `/opt/aMule-2.1.2/docs'
gmake[2]: Leaving directory `/opt/aMule-2.1.2/docs'
Making all in src
gmake[2]: Entering directory `/opt/aMule-2.1.2/src'
Making all in libs
gmake[3]: Entering directory `/opt/aMule-2.1.2/src/libs'
Making all in ec
gmake[4]: Entering directory `/opt/aMule-2.1.2/src/libs/ec'
gmake all-am
gmake[5]: Entering directory `/opt/aMule-2.1.2/src/libs/ec'
source='ECPacket.cpp' object='libec_noevt_a-ECPacket.o' libtool=no \
DEPDIR=.deps depmode=none /bin/bash ../../../depcomp \
g++ -DHAVE_CONFIG_H -I. -I. -I../../.. -I/usr/local/include -I/usr/lib/wx/include/gtk2-unicode-release-2.6 -I/usr/include/wx-2.6 -DGTK_NO_CHECK_CASTS -D__WXGTK__ -D_FILE_OFFSET_BITS=64 -D_LARGE_FILES -I../../../src -I../../../src/libs -DECSOCKET_USE_EVENTS=0 -DUSE_EMBEDDED_CRYPTO -W -Wall -Wshadow -Wundef -g -ggdb -fno-inline -D__DEBUG__ -fmessage-length=0 -D_GLIBCXX_DEBUG -D_GLIBCXX_DEBUG_PEDANTIC -c -o libec_noevt_a-ECPacket.o `test -f 'ECPacket.cpp' || echo './'`ECPacket.cpp
In file included from /usr/include/sys/wait.h:24,
from /usr/include/stdlib.h:22,
from /usr/include/wx-2.6/wx/string.h:43,
from ECPacket.h:28,
from ECPacket.cpp:25:
/usr/include/sys/siginfo.h:259: error: 'ctid_t' is used as a type, but is not defined as a type.
/usr/include/sys/siginfo.h:390: error: 'ctid_t' is used as a type, but is not defined as a type.
gmake[5]: *** [libec_noevt_a-ECPacket.o] Error 1
gmake[5]: Leaving directory `/opt/aMule-2.1.2/src/libs/ec'
gmake[4]: *** [all] Error 2
gmake[4]: Leaving directory `/opt/aMule-2.1.2/src/libs/ec'
gmake[3]: *** [all-recursive] Error 1
gmake[3]: Leaving directory `/opt/aMule-2.1.2/src/libs'
gmake[2]: *** [all-recursive] Error 1
gmake[2]: Leaving directory `/opt/aMule-2.1.2/src'
gmake[1]: *** [all-recursive] Error 1
gmake[1]: Leaving directory `/opt/aMule-2.1.2'
gmake: *** [all] Error 2