Hello Mathieu, I see the following compiler errors during the build phase when trying to build with `guix build --target=aarch64-linux-gnu lsof': dsock.c: In function ‘build_IPstates’: dsock.c:392:49: error: ‘TCP_ESTABLISHED’ undeclared (first use in this function) 392 | (void) enter_IPstate("TCP", "ESTABLISHED", TCP_ESTABLISHED); | ^~~~~~~~~~~~~~~ dsock.c:392:49: note: each undeclared identifier is reported only once for each function it appears in aarch64-linux-gnu-gcc -DLINUXV=00000 -DHASNORPC_H -D_FILE_OFFSET_BITS=64 -D_LARGEFILE64_SOURCE -DLSOF_VSTR=\"0.0.0\" -O -c -o usage.o usage.c dsock.c:393:46: error: ‘TCP_SYN_SENT’ undeclared (first use in this function); did you mean ‘TCP_SYNCNT’? 393 | (void) enter_IPstate("TCP", "SYN_SENT", TCP_SYN_SENT); | ^~~~~~~~~~~~ | TCP_SYNCNT dsock.c:394:46: error: ‘TCP_SYN_RECV’ undeclared (first use in this function) 394 | (void) enter_IPstate("TCP", "SYN_RECV", TCP_SYN_RECV); | ^~~~~~~~~~~~ dsock.c:395:47: error: ‘TCP_FIN_WAIT1’ undeclared (first use in this function) 395 | (void) enter_IPstate("TCP", "FIN_WAIT1", TCP_FIN_WAIT1); | ^~~~~~~~~~~~~ dsock.c:396:47: error: ‘TCP_FIN_WAIT2’ undeclared (first use in this function) 396 | (void) enter_IPstate("TCP", "FIN_WAIT2", TCP_FIN_WAIT2); | ^~~~~~~~~~~~~ dsock.c:397:47: error: ‘TCP_TIME_WAIT’ undeclared (first use in this function); did you mean ‘TCP_TIMESTAMP’? 397 | (void) enter_IPstate("TCP", "TIME_WAIT", TCP_TIME_WAIT); | ^~~~~~~~~~~~~ | TCP_TIMESTAMP dsock.c:398:43: error: ‘TCP_CLOSE’ undeclared (first use in this function); did you mean ‘TCP_CORK’? 398 | (void) enter_IPstate("TCP", "CLOSE", TCP_CLOSE); | ^~~~~~~~~ | TCP_CORK dsock.c:399:48: error: ‘TCP_CLOSE_WAIT’ undeclared (first use in this function) 399 | (void) enter_IPstate("TCP", "CLOSE_WAIT", TCP_CLOSE_WAIT); | ^~~~~~~~~~~~~~ dsock.c:400:46: error: ‘TCP_LAST_ACK’ undeclared (first use in this function); did you mean ‘TCP_FLAG_ACK’? 400 | (void) enter_IPstate("TCP", "LAST_ACK", TCP_LAST_ACK); | ^~~~~~~~~~~~ | TCP_FLAG_ACK dsock.c:401:44: error: ‘TCP_LISTEN’ undeclared (first use in this function); did you mean ‘TCP_FASTOPEN’? 401 | (void) enter_IPstate("TCP", "LISTEN", TCP_LISTEN); | ^~~~~~~~~~ | TCP_FASTOPEN dsock.c:402:45: error: ‘TCP_CLOSING’ undeclared (first use in this function); did you mean ‘POF_CLOSING’? 402 | (void) enter_IPstate("TCP", "CLOSING", TCP_CLOSING); | ^~~~~~~~~~~ | POF_CLOSING dsock.c: In function ‘get_tcpudp’: dsock.c:2998:20: error: ‘TCP_ESTABLISHED’ undeclared (first use in this function) 2998 | if (tp->state == TCP_ESTABLISHED) { | ^~~~~~~~~~~~~~~ dsock.c: In function ‘get_unix’: dsock.c:3527:64: error: ‘UINT32_MAX’ undeclared (first use in this function); did you mean ‘UINT_MAX’? 3527 | || (ty = (uint32_t)strtoul(fp[4], &ep, 16)) == (uint32_t)UINT32_MAX | ^~~~~~~~~~ | UINT_MAX make: *** [: dsock.o] Error 1 make: *** Waiting for unfinished jobs.... Checking the build log, I see the following error: Testing C library type with aarch64-linux-gnu-gcc ... ./Configure: line 2922: ./lsof_Configure_tmp_26.x: cannot execute binary file: Exec format error done Cannot determine C library type; assuming it is not glibc. So I believe the compiler errors are caused by attempting to build with glibc without adding glibc-specific build flags. The root cause of this is that the c library detection in lsof builds and runs a small program in order to see if it's using glibc. Since it is building this with the cross-compiler, the resulting binary (usually) won't be able to run on the host. If you have binfmt_misc + qemu set up on your machine, you may not see this error. The solution is to point LINUX_CONF_CC at the build machine's compiler instead of using the cross compiler for this step, which should build and execute the test program natively. Thanks, Brian