boost::filesystem::copy_file: Function not implemented (1.76)

[basiliscos]

Hi.

When I cross-compile boost for aarch64, and then run tests via qemu-aarch64 inside docker, I got the error. When there is no docker between, there is no problem, i.e. the same binary executes perfectly. Unfortunately, we use CI for testing, hence, it would be nice to let copy_file work.

As far as I was able to google, the issue is in fallocate syscall (aka 285) (see https://forums.percona.com/t/does-docker-use-unionfs-and-does-it-cause-fallocate-operation-not-supported/8161 )

Here is an excerpt of runnign qemu-aarch64 -strace -L /path/to/my/sysroot my-binary

607 newfstatat(AT_FDCWD,"/home/conan/b8f3-d6a1-a97d-8301.defaults",0x00000055007ffc60,0) = 0
file = /home/conan/b8f3-d6a1-a97d-8301.defaults
607 write(1,0x4f99e0,48) = 48
607 newfstatat(AT_FDCWD,"/home/conan/b8f3-d6a1-a97d-8301.defaults",0x00000055007ffaf0,0) = 0
607 newfstatat(AT_FDCWD,"/home/conan/b8f3-d6a1-a97d-8301",0x00000055007ffaf0,0) = -1 errno=2 (No such file or directory)
607 openat(AT_FDCWD,"/home/conan/b8f3-d6a1-a97d-8301.defaults",O_RDONLY|O_CLOEXEC) = 3
607 fstat(3,0x00000055007ffa70) = 0
607 openat(AT_FDCWD,"/home/conan/b8f3-d6a1-a97d-8301",O_WRONLY|O_CREAT|O_EXCL|O_TRUNC|O_CLOEXEC,S_IFREG|0644) = 4
607 fstat(4,0x00000055007ffaf0) = 0
607 Unknown syscall 285
607 futex(0x0000005500bff220,FUTEX_PRIVATE_FLAG|FUTEX_WAKE,2147483647,NULL,0x00000055009d5000,10309632) = 0
607 close(4) = 0
607 close(3) = 0
unknown file: Failure
607 write(1,0x4f99e0,22) = 22
C++ exception with description "boost::filesystem::copy_file: Function not implemented: "/home/conan/b8f3-d6a1-a97d-8301.defaults", "/home/conan/b8f3-d6a1-a97d-8301"" thrown in the test body.

It would be nice to have an option for fall back to other implementation, when possible.

Thanks!

[Lastique]

Boost.Filesystem does not use fallocate. Most likely you're missing copy_file_range or statx syscalls. Duplicates #172.