ld cannot find -latomic or -lstdc++ - c++

Question

When trying to compile my project using the toolchain provided by the manufacturer of the hardware I'm developing for, compilation succeeds, however linking fails with the following error messages:
/media/xxx/Data/toolchains/sysroots/x86_64-xxx-linux/usr/bin/arm-xxx-linux-gnueabi/../../libexec/arm-xxx-linux-gnueabi/gcc/arm-xxx-linux-gnueabi/4.8.4/ld: cannot find -latomic
/media/xxx/Data/toolchains/sysroots/x86_64-xxx-linux/usr/bin/arm-xxx-linux-gnueabi/../../libexec/arm-xxx-linux-gnueabi/gcc/arm-xxx-linux-gnueabi/4.8.4/ld: cannot find -lstdc++
However, when building a small test program using the same compiler and linker, everything works.
Below is an excerpt of the important parts of my CMake toolchain file:
set(CMAKE_SYSTEM_NAME Linux)
set(CMAKE_SYSTEM_PROCESSOR arm)
###
# Get $CROSS
###
if (NOT $ENV{CROSS_COMPILE} STREQUAL "")
set(cross $ENV{CROSS_COMPILE}) # WARNING: Ends with a - (minus)
else()
set(cross "arm-xxx-linux-gnueabi-")
endif()
###
# Set CMake sysroot
###
set(CMAKE_SYSROOT $ENV{SDKTARGETSYSROOT})
set(CMAKE_SYSROOT_LINK $ENV{SDKTARGETSYSROOT})
set(CMAKE_SYSROOT_COMPILE $ENV{SDKTARGETSYSROOT})
set(CMAKE_C_COMPILER $ENV{TOOLCHAIN_TOOLSDIR}/${cross}gcc)
set(CMAKE_CXX_COMPILER $ENV{TOOLCHAIN_TOOLSDIR}/${cross}g++)
set(CMAKE_LD $ENV{TOOLCHAIN_TOOLSDIR}/${cross}ld)
set(CMAKE_STRIP $ENV{TOOLCHAIN_TOOLSDIR}/${cross}strip)
set(CMAKE_AR $ENV{TOOLCHAIN_TOOLSDIR}/${cross}ar)
include_directories($ENV{SDKTARGETSYSROOT}/usr/include)
I'm not at liberty to disclose source code, but the source code isn't the issue here as it compiles correctly.
Here's another MWE of the CMakeLists.txt file:
cmake_minimum_required(VERSION 3.10)
project(xxx LANGUAGES CXX VERSION 2.0.0)
set(CMAKE_CXX_STANDARD 11)
set(CMAKE_CXX_STANDARD_REQUIRED True)
set(TARGET_NAME xxx.bin)
include_directories(
include/
${INCLUDE_DIRS}
)
file(GLOB_RECURSE FILES ${CMAKE_CURRENT_SOURCE_DIR} FOLLOW_SYMLINKS src/*.cpp)
if (xxx_DEBUG)
add_compile_options(
-Wpedantic
-DDDC_STUB
-fabi-version=6
-Wno-format-security
-Wno-reorder
-ggdb3
-O0
-fpermissive # Test
-fPIC
#-static-libstdc++ # with or without, doesn't change the behaviour
#-static-libgcc # with or without, doesn't change the behaviour
)
else()
add_compile_options(
-Wpedantic
-fabi-version=6
-Wno-format-security
-Wno-reorder
-O3
-fpermissive # Test
-fPIC
#-static-libstdc++ # with or without, doesn't change the behaviour
#-static-libgcc # with or without, doesn't change the behaviour
)
endif()
add_executable(${TARGET_NAME} ${FILES} ${MEMWATCH_FILES})
I've tried setting the sysroot-argument for ld, I've tried manually specifying the link (search) path -L$ENV{SDKTARGETSYSROOT}/usr/lib/.debug, and I've also tried hard-wiring the path to the library in question: $ENV{SDKTARGETSYSROOT}/usr/lib/.debug/libatomic.so.1.0.0
Is there another way I can tell ld what libraries to use?
This works perfectly with standard toolchains!
EDIT:
I've now also tried brute-forcing it by creating a symlink from the .debug/libatomic to usr/lib/libatomic. That also hasn't had the desired effect.