4.0 CI: add sccache

Ubuntu 26.04 has an sccache that comes with S3 support, rest needs to
build it.

Signed-off-by: Marcus Müller <mueller@baseband.digital>

Author: Marcus Müller

ci/ci-fedora-44-4.0/Dockerfile

@@ -1,6 +1,28 @@
 ARG FEDORA_VERSION=44
 ARG DNF_COMMAND="dnf --setopt=install_weak_deps=False -q"
 
+# Fedora >=43 has sccache, but none with S3 storage support
+ARG SCCACHE_VERSION=0.10.0
+ARG LIBAD9361_TAG=v0.3
+# ---- sccache takes a while to build (it's rust…) and
+#      quite a bit of space (it's cargo), so:
+# avoid rebuilding if version hasn't changed
+FROM fedora:${FEDORA_VERSION} AS sccache-builder
+ARG SCCACHE_VERSION
+ARG DNF_COMMAND
+LABEL maintainer="mmueller@gnuradio.org"
+RUN ${DNF_COMMAND} install --refresh -y \
+        cargo \
+        openssl-devel \
+        && ${DNF_COMMAND} clean all
+
+RUN cargo install \
+        --locked \
+        --quiet \
+        --target-dir /build \
+        --root /target \
+        sccache@${SCCACHE_VERSION} \
+        && rm -rf /build
 
 FROM fedora:${FEDORA_VERSION}
 ARG DNF_COMMAND
@@ -59,4 +81,6 @@ RUN ${DNF_COMMAND} update -y \
 RUN git clone --branch v0.4.4 --depth 1 https://github.com/mattkretz/vir-simd.git /opt/vir-simd \
     && cmake -E copy_directory /opt/vir-simd/vir /usr/local/include/vir \
     && rm -rf /opt/vir-simd
-    
+
+# Copy over sccache
+COPY --from=sccache-builder /target/bin/sccache /usr/bin/sccache

ci/ci-ubuntu-24.04-4.0-emscripten/Dockerfile

@@ -1,8 +1,31 @@
 ARG UBUNTU_VERSION=24.04
+ARG SCCACHE_VERSION=0.10.0
 ARG APT_INSTALL_COMMAND="apt-get install -qy --no-install-recommends"
 ARG EMSDK_VERSION=5.0.2
 
 
+FROM ubuntu:${UBUNTU_VERSION} AS sccache-builder
+ARG SCCACHE_VERSION
+ARG APT_INSTALL_COMMAND
+LABEL maintainer="mmueller@gnuradio.org"
+
+ENV DEBIAN_FRONTEND=noninteractive
+RUN apt-get update -q ;\
+    ${APT_INSTALL_COMMAND} \
+    cargo \
+    ca-certificates \
+    pkg-config \
+    libssl-dev \
+    && apt-get clean
+RUN cargo install \
+    --locked \
+    --quiet \
+    --target-dir /build \
+    --root /target \
+    sccache@${SCCACHE_VERSION} \
+    && rm -rf /build
+
+
 FROM ubuntu:${UBUNTU_VERSION}
 ARG APT_INSTALL_COMMAND
 ARG EMSDK_VERSION
@@ -54,3 +77,6 @@ RUN update-alternatives --install /usr/bin/gcc gcc /usr/bin/gcc-14 140 \
         --slave /usr/bin/g++ g++ /usr/bin/g++-14 \
         --slave /usr/bin/gcov gcov /usr/bin/gcov-14 \
     && update-alternatives --install /usr/bin/c++ c++ /usr/bin/g++-14 140
+
+# Copy over sccache
+COPY --from=sccache-builder /target/bin/sccache /usr/bin/sccache

ci/ci-ubuntu-24.04-4.0/Dockerfile

@@ -1,5 +1,27 @@
 ARG UBUNTU_VERSION=24.04
 ARG APT_INSTALL_COMMAND="apt-get install -qy --no-install-recommends"
+ARG SCCACHE_VERSION=0.10.0
+
+FROM ubuntu:${UBUNTU_VERSION} AS sccache-builder
+ARG SCCACHE_VERSION
+ARG APT_INSTALL_COMMAND
+LABEL maintainer="mmueller@gnuradio.org"
+
+ENV DEBIAN_FRONTEND=noninteractive
+RUN apt-get update -q ;\
+    ${APT_INSTALL_COMMAND} \
+    cargo \
+    ca-certificates \
+    pkg-config \
+    libssl-dev \
+    && apt-get clean
+RUN cargo install \
+    --locked \
+    --quiet \
+    --target-dir /build \
+    --root /target \
+    sccache@${SCCACHE_VERSION} \
+    && rm -rf /build
 
 
 FROM ubuntu:${UBUNTU_VERSION}
@@ -106,3 +128,6 @@ RUN git clone https://github.com/boost-ext/ut.git /tmp/ut \
 RUN git clone --branch v0.4.4 --depth 1 https://github.com/mattkretz/vir-simd.git /opt/vir-simd \
     && cmake -E copy_directory /opt/vir-simd/vir /usr/local/include/vir \
     && rm -rf /opt/vir-simd
+
+# Copy over sccache
+COPY --from=sccache-builder /target/bin/sccache /usr/bin/sccache

ci/ci-ubuntu-26.04-4.0/Dockerfile

@@ -1,7 +1,6 @@
 ARG UBUNTU_VERSION=26.04
 ARG APT_INSTALL_COMMAND="apt-get install -qy --no-install-recommends"
 
-
 FROM ubuntu:${UBUNTU_VERSION}
 ARG APT_INSTALL_COMMAND
 
@@ -19,6 +18,7 @@ RUN apt-get update -q \
         build-essential \
         ca-certificates \
         ccache \
+        sccache \
         cmake \
         file \
         git \