docs: "docker compose cp -L" does not dereference symlinks in directory

[pzhlkj6612]

Hi!

Before:

$ ls -g -o ./opt/usr/i686-w64-mingw32/bin/
total 14452
lrwxrwxrwx 1       29 Jan 25  2024 ar -> ../../bin/i686-w64-mingw32-ar
lrwxrwxrwx 1       29 Jan 25  2024 as -> ../../bin/i686-w64-mingw32-as
lrwxrwxrwx 1       34 Jan 25  2024 dlltool -> ../../bin/i686-w64-mingw32-dlltool
lrwxrwxrwx 1       29 Jan 25  2024 ld -> ../../bin/i686-w64-mingw32-ld
lrwxrwxrwx 1       29 Jan 25  2024 ld.bfd -> ../../bin/i686-w64-mingw32-ld
lrwxrwxrwx 1       29 Jan 25  2024 nm -> ../../bin/i686-w64-mingw32-nm
lrwxrwxrwx 1       34 Jan 25  2024 objcopy -> ../../bin/i686-w64-mingw32-objcopy
lrwxrwxrwx 1       34 Jan 25  2024 objdump -> ../../bin/i686-w64-mingw32-objdump
lrwxrwxrwx 1       20 Dec 27 18:12 protoc.exe -> protoc.exe-3.21.12.0
-rwxr-xr-x 1 14797564 Dec 27 18:12 protoc.exe-3.21.12.0
lrwxrwxrwx 1       33 Jan 25  2024 ranlib -> ../../bin/i686-w64-mingw32-ranlib
lrwxrwxrwx 1       34 Jan 25  2024 readelf -> ../../bin/i686-w64-mingw32-readelf
lrwxrwxrwx 1       32 Jan 25  2024 strip -> ../../bin/i686-w64-mingw32-strip

After:

$ ls -g -o ./opt/usr/i686-w64-mingw32/bin/
total 44776
-rwxr-xr-x 1  1164680 Jan 25  2024 ar
-rwxr-xr-x 1  1805360 Jan 25  2024 as
-rwxr-xr-x 1  1201736 Jan 25  2024 dlltool
-rwxr-xr-x 2  1752048 Jan 25  2024 ld
-rwxr-xr-x 2  1752048 Jan 25  2024 ld.bfd
-rwxr-xr-x 1  1157440 Jan 25  2024 nm
-rwxr-xr-x 1  1283528 Jan 25  2024 objcopy
-rwxr-xr-x 1  2642464 Jan 25  2024 objdump
-rwxr-xr-x 2 14797564 Dec 27 18:12 protoc.exe
-rwxr-xr-x 2 14797564 Dec 27 18:12 protoc.exe-3.21.12.0
-rwxr-xr-x 1  1164712 Jan 25  2024 ranlib
-rwxr-xr-x 1  1022864 Jan 25  2024 readelf
-rwxr-xr-x 1  1283528 Jan 25  2024 strip

Ref:

• docker cp --follow-link does not work as expected moby/moby#30213

[pzhlkj6612]

Using ./scripts/tools.sh compose-cmd ... looks better IMO.

[pzhlkj6612]

I have a question: Are we making a sysroot? If so, the CMAKE_SYSROOT should be configurable.

ra2yrcpp/toolchains/mingw-w64-i686.cmake

Line 4 in 860efec

set(CMAKE_SYSROOT /usr/${TOOLCHAIN_PREFIX})

After patching the toolchain cmake file, I still need to specify PROTOC_PATH to $PWD/opt/bin/protoc. If we will have a configurable sysroot, maybe we can directly copy "protoc" to opt/usr/i686-w64-mingw32/bin (or ln -s ../../../bin/protoc ./opt/usr/i686-w64-mingw32/bin/protoc). After that, building on the host may become easier.