Update to Debian Trixie

I had two MIPS-related hiccups with this:
- the musl-upstream `musl-gcc` wrapper script has a bug that drops compiler arguments (patch included here; hopefully we can remove in the future?)
- QEMU couldn't run the resulting MUSL binaries until I applied an update to my binfmt magic/mask (https://bugs.debian.org/1041597, bb0811e353) - it also runs just fine on real musl hardware

Dockerfile.build

@@ -1,10 +1,9 @@
 # explicitly use Debian for maximum cross-architecture compatibility
-FROM debian:bookworm-slim
+FROM debian:trixie-slim
 
 RUN set -eux; \
-	apt-get update; \
 	dpkgArch="$(dpkg --print-architecture)"; \
-	apt-get install -y --no-install-recommends \
+	apt-get install --update -y --no-install-recommends \
 		ca-certificates \
 		gnupg \
 		wget \
@@ -37,8 +36,9 @@ RUN set -eux; \
 		\
 		arch-test \
 		file \
+		patch \
 	; \
-	rm -rf /var/lib/apt/lists/*
+	apt-get dist-clean
 
 # https://musl.libc.org/releases.html
 ENV MUSL_VERSION 1.2.5
@@ -59,6 +59,9 @@ RUN set -eux; \
 WORKDIR /usr/src/hello
 COPY . .
 
+# https://bugs.debian.org/1050429: error: unrecognized command-line option '-EL' (on mips64le specifically/only)
+RUN patch --input="$PWD/musl-gcc-mips64le.patch" /usr/local/src/musl/tools/musl-gcc.specs.sh
+
 # the following steps are grouped into "architecture families" and roughly ordered in a descending compatibility way such that we end up with the most accurate ".host-arch" symlink we can reasonably get
 
 RUN set -ex; \

Makefile

@@ -20,6 +20,8 @@ $(MUSL_GCC):
 	mkdir -p '$(MUSL_DIR)'
 	cd '$(MUSL_DIR)' && '$(MUSL_SRC)/configure' --disable-shared --prefix='$(MUSL_PREFIX)' > /dev/null
 	$(MAKE) -C '$(MUSL_DIR)' -j '$(shell nproc)' install > /dev/null
+.PHONY: musl
+musl: $(MUSL_GCC)
 
 $(C_TARGETS): hello.c $(MUSL_GCC)
 	$(MUSL_GCC) $(CFLAGS) -Wl,--gc-sections -static \

musl-gcc-mips64le.patch

@@ -0,0 +1,19 @@
+Origin: https://bugs.debian.org/1050429#64
+
+--- tools/musl-gcc.specs.sh	2024-03-01 02:07:33.000000000 +0000
++++ tools/musl-gcc.specs.sh.new	2025-06-17 21:19:01.669504848 +0000
+@@ -3,12 +3,13 @@
+ ldso=$3
+ cat <<EOF
+ %rename cpp_options old_cpp_options
++%rename cc1 old_cc1
+ 
+ *cpp_options:
+ -nostdinc -isystem $incdir -isystem include%s %(old_cpp_options)
+ 
+ *cc1:
+-%(cc1_cpu) -nostdinc -isystem $incdir -isystem include%s
++-nostdinc -isystem $incdir -isystem include%s %(old_cc1)
+ 
+ *link_libgcc:
+ -L$libdir -L .%s