I receive this error after running make px4fmu-v2_default. It has something to do with rsync. A window popped up after first running this wanting me to allow rsync to get through private networks and I confirm. But still retrieving this error after each attempt.
$ make px4fmu-v2_default
[ 0%] Built target git_nuttx
[ 0%] Built target git_gencpp
[ 1%] Built target ver_gen
[ 1%] Built target git_genmsg
[ 1%] Built target git_mavlink
[ 1%] Built target git_uavcan
[ 1%] Built target git_matrix
[ 1%] Built target git_ecl
[ 1%] Built target mixer_gen
[ 2%] Built target xml_gen
[ 2%] [ 2%] Copying NuttX for px4io-v2 with nshCopying NuttX for px4fmu-v2 with nsh
rsync: writefd_unbuffered failed to write 4 bytes to socket [sender]: Connection reset by peer (104)rsync: writefd_unbuffered failed to write 4 bytes to socket [sender]: Connection reset by peer (104)
rsync: mkdir “/usr/home/otisj/src/Firmware/build_px4fmu-v2_default/px4io-v2/NuttX” failed: Bad file number (9)rsync: mkdir “/usr/home/otisj/src/Firmware/build_px4fmu-v2_default/px4fmu-v2/NuttX” failed: Bad file number (9)
rsync error: error in file IO (code 11) at /usr/src/rsync/rsync-3.0.8/main.c(587) [Receiver=3.0.8]rsync error: error in file IO (code 11) at /usr/src/rsync/rsync-3.0.8/main.c(587) [Receiver=3.0.8]
rsync: connection unexpectedly closed (9 bytes received so far) [sender]rsync: connection unexpectedly closed (9 bytes received so far) [sender]
rsync error: error in rsync protocol data stream (code 12) at /usr/src/rsync/rsync-3.0.8/io.c(601) [sender=3.0.8]
rsync error: error in rsync protocol data stream (code 12) at /usr/src/rsync/rsync-3.0.8/io.c(601) [sender=3.0.8]
make[3]: make[3]: *** [nuttx_copy_px4fmu-v2.stamp] Error 12*** [nuttx_copy_px4io-v2.stamp] Error 12
make[2]: *** [CMakeFiles/nuttx_copy_px4fmu-v2.dir/all] Error 2
make[2]: *** Waiting for unfinished jobs…
make[2]: *** [src/modules/px4iofirmware/CMakeFiles/nuttx_copy_px4io-v2.dir/all] Error 2
make[1]: *** [all] Error 2
make: *** [px4fmu-v2_default] Error 2