当我make在 Ubuntu 12.04 下的 ns2 上运行修补 CRCN 的命令时，我遇到了这个错误：
make[1]: Entering directory `/home/apadana/ns-allinone-2.31/ns-2.31/indep-utils/cmu-scen-gen/setdest'
make[1]: Nothing to be done for `all'.
make[1]: Leaving directory `/home/apadana/ns-allinone-2.31/ns-2.31/indep-utils/cmu-scen-gen/setdest'
make[1]: Entering directory `/home/apadana/ns-allinone-2.31/ns-2.31/indep-utils/webtrace-conv/dec'
make[1]: Nothing to be done for `all'.
make[1]: Leaving directory `/home/apadana/ns-allinone-2.31/ns-2.31/indep-utils/webtrace-conv/dec'
make[1]: Entering directory `/home/apadana/ns-allinone-2.31/ns-2.31/indep-utils/webtrace-conv/epa'
make[1]: Nothing to be done for `all'.
make[1]: Leaving directory `/home/apadana/ns-allinone-2.31/ns-2.31/indep-utils/webtrace-conv/epa'
make[1]: Entering directory `/home/apadana/ns-allinone-2.31/ns-2.31/indep-utils/webtrace-conv/nlanr'
make[1]: Nothing to be done for `all'.
make[1]: Leaving directory `/home/apadana/ns-allinone-2.31/ns-2.31/indep-utils/webtrace-conv/nlanr'
make[1]: Entering directory `/home/apadana/ns-allinone-2.31/ns-2.31/indep-utils/webtrace-conv/ucb'
make[1]: Nothing to be done for …kernel ×1