[libpq] build failure

[Sallee1]

Operating system

Windows 11 Pro 24H2 26100.3476

Compiler

arm-gnu-toolchain-14.2.rel1-mingw-w64-x86_64-aarch64-none-linux-gnu

Steps to reproduce the behavior

1. Downloaded and installed the AArch64 GNU/Linux target (aarch64-none-linux-gnu) toolchain for cross-compilation from https://developer.arm.com/downloads/-/arm-gnu-toolchain-downloads. The compiler was installed to C:\ProgramData\gcc-aarch64-linux-gnu and added to the PATH environment variable.

2. Created a custom toolchain to bypass the original vcpkg.cmake, which failed to locate the cross-compilation compiler:

C:\ProgramData\gcc-aarch64-linux-gnu\gcc-aarch64-linux-gnu.cmake

set(CMAKE_SYSTEM_NAME Linux)
set(CMAKE_SYSTEM_PROCESSOR aarch64)
set(CMAKE_C_COMPILER "C:/ProgramData/gcc-aarch64-linux-gnu/bin/aarch64-none-linux-gnu-gcc.exe")
set(CMAKE_CXX_COMPILER "C:/ProgramData/gcc-aarch64-linux-gnu/bin/aarch64-none-linux-gnu-g++.exe")

3. Modified .\triplets\community\arm64-linux.cmake to point to the custom toolchain:

set(VCPKG_TARGET_ARCHITECTURE arm64)
set(VCPKG_CRT_LINKAGE dynamic)
set(VCPKG_LIBRARY_LINKAGE dynamic)

set(VCPKG_CMAKE_SYSTEM_NAME Linux)
set(VCPKG_BUILD_TYPE release)

set(VCPKG_FIXUP_ELF_RPATH ON)

set(VCPKG_CHAINLOAD_TOOLCHAIN_FILE "C:/ProgramData/gcc-aarch64-linux-gnu/gcc-aarch64-linux-gnu.cmake")

4. Installation command:
   .\vcpkg.exe install gdal --triplet=arm64-linux

   The compilation of libpq (a sub-step for building GDAL) failed. Libraries like zlib and curl compiled successfully, and their outputs were confirmed to use the ARM64 instruction set.

   The error can also be reproduced via:
   .\vcpkg.exe install libpq --triplet=arm64-linux

Failure logs

issue_body.md

Additional context

After analyzing the error logs, I suspect that during the configuration phase, libpq mistakenly identified the toolchain as MinGW instead of arm64-linux, and subsequently added the non-existent parameter --enable-auto-import during the linking stage.