looks like 3.25 doesnt work either

docker/linux_arm64/Dockerfile

@@ -9,14 +9,16 @@ RUN apt-get install -y -qq ccache autoconf
 # Setup cross compiler because GH actions does not have open source arm runners yet
 RUN apt-get install -y -qq gcc-aarch64-linux-gnu g++-aarch64-linux-gnu
 
-# Install cmake 3.25
+# Install cmake 3.21
 # Somehow, recursive-cmake based builds fail when cross-compiling with cmake 3.31,
-# So we revert to using 3.25 for now. We should bisect and investigate this further later.
-RUN mkdir /cmake_3_25 && \
-    cd /cmake_3_25 && \
-    wget https://github.com/Kitware/CMake/releases/download/v3.25.3/cmake-3.25.3-linux-x86_64.sh && \
-    chmod +x cmake-3.25.3-linux-x86_64.sh && \
-    ./cmake-3.25.3-linux-x86_64.sh --skip-license --prefix=/usr/local && \
+# so we revert to using 3.21 for now. We should investigate this further.
+# I've done some initial bisecting, and it seems like 3.25 also fails.
+# So somewhere between 3.21 and 3.25, something changed in cmake that breaks recursive-cmake CC-builds.
+RUN mkdir /cmake_3_21 && \
+    cd /cmake_3_21 && \
+    wget https://github.com/Kitware/CMake/releases/download/v3.21.3/cmake-3.21.3-linux-x86_64.sh && \
+    chmod +x cmake-3.21.3-linux-x86_64.sh && \
+    ./cmake-3.21.3-linux-x86_64.sh --skip-license --prefix=/usr/local && \
     cmake --version
 
 # Install GIT