Fix installing dependencies via cpan in docker

Dockerfile

@@ -1,31 +1,44 @@
 # Dockerfile by Sébastien HOUZÉ, https://github.com/shouze
-FROM perl:slim AS base
+FROM perl:slim AS builder
 
 RUN export DEBIAN_FRONTEND=noninteractive \
  && apt-get update \
  && apt-get install -y --no-install-recommends \
-    ca-certificates \
-    git \
-    unzip \
     dos2unix \
- && rm -rf /var/lib/apt/lists/*
+    gcc
 
 #Install all dependencies
-# 2024-01-19 cpanm command has been failing -- no explanation
-#RUN cpanm \
-#      Algorithm::Diff \
-#      Digest::MD5 \
-#      Parallel::ForkManager \
-#      Regexp::Common \
-# && rm -rf $HOME/.cpanm
+RUN cpanm \
+      Algorithm::Diff \
+      Digest::MD5 \
+      Parallel::ForkManager \
+      Regexp::Common
 
 #Copy source code
 COPY cloc /usr/src/
 RUN find /usr/src/ -type f -exec dos2unix {} \;
 
+FROM perl:slim AS base
+
+RUN export DEBIAN_FRONTEND=noninteractive \
+ && apt-get update \
+ && apt-get install -y --no-install-recommends \
+    git \
+    unzip \
+ && rm -rf /var/lib/apt/lists/*
+
+#Copy dependencies and source prepared in base image
+COPY --from=builder /usr/local/lib/perl5 /usr/local/lib/perl5
+COPY --from=builder /usr/src/ /usr/src/
+
 ####################
 FROM base AS test
 
+RUN export DEBIAN_FRONTEND=noninteractive \
+ && apt-get update \
+ && apt-get install -y --no-install-recommends \
+    ca-certificates
+
 #Copy test code
 COPY .git /usr/src/.git
 COPY tests /usr/src/tests