build: Use docker volumes instead of bind-mounts to speed up kernel build on macOS

[robin-reckmann]

Docker bind mounts are really slow on macOS. So creating a docker volumes of the kernel and ccache and building on there speeds up the overall build a lot.

	volume	bind-mount	improvement
build from scratch	16min 0sec	18min 14sec	1.13x
re-build after removing out/	0min 42sec	2min 6sec	3x
re-build without changes	0min 32sec	2min 6sec	3.9x

[github-actions]

vamOS System Profile

Changes vs master

Metric	Change
Used space	3486.4MB → 3486.8MB (+.4MB)
Sparse image	3440.9MB → 3440.4MB (-.4MB)
Package count	524 → 524

Added packages: alacritty-terminfo-0.17.0_1, dhcpcd-10.3.1_1, htop-3.5.0_1, libjpeg-turbo-3.1.4.1_1, libnfsidmap-2.9.1_1, libpng-1.6.57_1, libpng-devel-1.6.57_1, libsodium-1.0.22_1, libsodium-devel-1.0.22_1, logrotate-3.22.0_2, nfs-utils-2.9.1_1, openssh-10.3p1_1, python3-3.14.4_1, stress-ng-0.21.00_1, wayland-1.25.0_1, wayland-devel-1.25.0_1, wayland-protocols-1.48_1

Removed packages: alacritty-terminfo-0.16.1_1, dhcpcd-10.3.0_1, htop-3.4.1_1, libjpeg-turbo-3.1.1_1, libnfsidmap-2.8.7_1, libpng-1.6.56_1, libpng-devel-1.6.56_1, libsodium-1.0.21_1, libsodium-devel-1.0.21_1, logrotate-3.22.0_1, nfs-utils-2.8.7_1, openssh-10.2p1_1, python3-3.14.3_1, stress-ng-0.20.01_1, wayland-1.24.0_1, wayland-devel-1.24.0_1, wayland-protocols-1.47_1

Directory size changes (>1MB)

Directory	Change

---

Metric	Value
Used space	3486.8MB / 5959.5MB
Files	56353
Directories	4763
Symlinks	3602
Packages	524

Top 10 Directories

Directory	Size

Category Breakdown

Category	Size	%
xbps packages	2490.2MB	71.4%
Python venv	655.3MB	18.7%
Firmware	11.5MB	.3%
Other	329.6MB	9.4%

Top 10 Packages by Size

Package	Size
mit-krb5-libs-1.21.3_1	270.4MB
gawk-5.3.2_1	210.3MB
llvm-21_3	148.6MB
libldns-1.9.0_1	124.3MB
pd-mapper-1.0_1	73.9MB
libclang21-21.1.7_1	70.2MB
glib-2.88.0_1	67.4MB
gcc-14.2.1+20250405_4	65.4MB
libcap-progs-2.77_1	56MB
cmake-4.2.2_1	53.2MB

Top 30 Files by Size

File	Size
/usr/lib/llvm/21/lib/libLLVM.so.21.1	124.3MB
/usr/lib/llvm/21/lib/libMLIR.so.21.1	89.7MB
/usr/lib/llvm/21/bin/mlir-transform-opt	82.9MB
/usr/lib/llvm/21/lib/libclang-cpp.so.21.1	56MB
/usr/lib/llvm/21/bin/mlir-translate	53.2MB
/usr/lib/llvm/21/bin/llvm-exegesis	52MB
/usr/lib/llvm/21/bin/llvm-bolt-binary-analysis	50.6MB
/usr/local/venv/lib/python3.12/site-packages/ffmpeg/install/lib/libavcodec.a	50.5MB
/usr/bin/uv	49.1MB
/usr/lib/gcc/aarch64-linux-gnu/14.2/gnat1	40.1MB
/usr/bin/gdb	38.1MB
/usr/lib/gcc/aarch64-linux-gnu/14.2/cc1plus	37.3MB
/usr/lib/libgallium-25.3.3.so	35.4MB
/usr/lib/libllvm-qcom.so	35.2MB
/usr/lib/gcc/aarch64-linux-gnu/14.2/cc1	35.2MB
/usr/lib/gcc/aarch64-linux-gnu/14.2/lto1	33.9MB
/usr/bin/lto-dump	33.9MB
/usr/lib/libRusticlOpenCL.so.1.0.0	32.5MB
/usr/local/venv/bin/ruff	31.8MB
/usr/share/icu/78.2/icudt78l.dat	31.5MB
/usr/lib/llvm/21/lib/libclang.so.21.1.7	30.2MB
/usr/lib/llvm/21/bin/c-index-test	28.6MB
/usr/local/venv/lib/python3.12/site-packages/gcc_arm_none_eabi/toolchain/libexec/gcc/arm-none-eabi/13.2.1/cc1	28.2MB
/usr/lib/libz3.so	27.9MB
/usr/bin/run	26.6MB
/usr/local/venv/lib/python3.12/site-packages/numpy.libs/libscipy_openblas64_-71e1b124.so	23.6MB
/usr/comma/updater	23.5MB
/usr/comma/setup	23.5MB
/usr/comma/reset	23.5MB
/usr/local/uv/python/cpython-3.12.13-linux-aarch64-gnu/bin/python3.12	22.1MB