Why does one of my finaries fail with version `GLIBC_2.27' not found

Question

I am cross-compiling by binaries identically by CMake clauses like

add_executable(mybinary1 mybinary1.c util_temp.c)
target_link_libraries(mybinary1 m)

add_executable(mybinary2 mybinary2.c util_temp.c)
target_link_libraries(mybinary2 m)

Unfortunately, one of them fails when running on target platform:

/mybinary2: /lib/arm-linux-gnueabihf/libm.so.6: version `GLIBC_2.27' not found (required by ./mybinary2)

First binary runs well.

ldd shows

# ldd mybinary2
./mybinary2: /lib/arm-linux-gnueabihf/libm.so.6: version `GLIBC_2.27' not found (required by ./mybinary2)
    linux-vdso.so.1 (0x7ed1d000)
    /usr/lib/arm-linux-gnueabihf/libarmmem.so (0x76fa2000)
    libm.so.6 => /lib/arm-linux-gnueabihf/libm.so.6 (0x76f27000)
    libc.so.6 => /lib/arm-linux-gnueabihf/libc.so.6 (0x76de6000)
    /lib/ld-linux-armhf.so.3 (0x76fcc000)
# ldd mybinary1
    linux-vdso.so.1 (0x7ee09000)
    /usr/lib/arm-linux-gnueabihf/libarmmem.so (0x76ece000)
    libm.so.6 => /lib/arm-linux-gnueabihf/libm.so.6 (0x76e53000)
    libc.so.6 => /lib/arm-linux-gnueabihf/libc.so.6 (0x76d12000)
    /lib/ld-linux-armhf.so.3 (0x76efb000)

What does it mean and how to solve it? Can I compile against specific version of a library? Why does it refer GLIBS indirectly, via libm?

If I do

target_link_libraries(mybinary2 m -static)

it starts to work but binary becomes x20 larger.

I also tried

__asm__(".symver realpath,realpath@GLIBC_2.19");
int main(int argc, char *argv[])

in mybinary2.c with no effect.

target_link_libraries(mybinary2 m -static-libgcc -static-libstdc++)

in CMakeLists.txt with no effect.

target_link_libraries(mybinary2 m libc.so.6:2.19)

with error message

[build] /usr/lib/gcc-cross/arm-linux-gnueabihf/7/../../../../arm-linux-gnueabihf/bin/ld: cannot find -llibc.so.6:2.19

Is latter syntax correct? How to see, which version (and of what) is on my system?

I tried commands like

ld -llibc

but neither work.

On my target computer (it is Raspberry Pi with old version of OS):

# ldd --version
ldd (Debian GLIBC 2.19-18+deb8u10) 2.19
Copyright (C) 2014 Free Software Foundation, Inc.
This is free software; see the source for copying conditions.  There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
Written by Roland McGrath and Ulrich Drepper.

I don't know how to use cross ldd on source computer.

Answer 1

Based on what your target computer outputs via ldd --version and based on the error (which also explains why a static link works):

You have a GLIBC version mismatch, i.e. you compile it using GLIBC 2.27 but on the target computer you have GLIBC 2.19. You either need to crosscompile with a lower version than you are currently using or upgrade glibc on the target computer.

EDIT: To clarify which errors and general info I mean:

1)

# ldd mybinary2
./mybinary2: /lib/arm-linux-gnueabihf/libm.so.6: version `GLIBC_2.27' not found (required by ./mybinary2)

# ldd --version
ldd (Debian GLIBC 2.19-18+deb8u10) 2.19

EDIT2: Did a quick search and assuming you are crosscompiling on debian you could use the following command to get available package versions:

apt-cache policy myPackage

Where myPackage will most likely be libc6-dev-armhf-cross for your current needs.

EDIT3: As Andrew Henle pointed out. The easiest solution is to directly compile your project on the target device (or a compilation environment that is identical to the one on the target). Consider the above only if the target device is limiting you in doing so.