Merge pull request #238 from rstudio/focal-blas

Fix BLAS portability issues with Ubuntu 20.04 R builds

builder/Dockerfile.debian-12

@@ -7,7 +7,7 @@ RUN set -x \
   && echo 'deb-src http://deb.debian.org/debian bookworm main' >> /etc/apt/sources.list \
   && apt-get update \
   && apt-get install -y curl gcc libcurl4-openssl-dev libicu-dev \
-     libopenblas0 libpcre2-dev make unzip wget \
+     libopenblas0-pthread libpcre2-dev make unzip wget \
   && apt-get build-dep -y r-base
 
 # Install AWS CLI

builder/Dockerfile.ubuntu-2004

@@ -6,7 +6,7 @@ RUN set -x \
   && sed -i "s|# deb-src|deb-src|g" /etc/apt/sources.list \
   && export DEBIAN_FRONTEND=noninteractive \
   && apt-get update \
-  && apt-get install -y curl libopenblas-dev libcurl4-openssl-dev libicu-dev liblapack-dev libpcre2-dev wget python3-pip \
+  && apt-get install -y curl libopenblas0-pthread libcurl4-openssl-dev libicu-dev liblapack-dev libpcre2-dev wget python3-pip \
   && apt-get build-dep -y r-base
 
 RUN pip3 install awscli

builder/Dockerfile.ubuntu-2404

@@ -6,6 +6,13 @@ RUN set -x \
   && sed -i "s|Types: deb|Types: deb deb-src|g" /etc/apt/sources.list.d/ubuntu.sources \
   && export DEBIAN_FRONTEND=noninteractive \
   && apt update \
+  # For BLAS/LAPACK, select the library-only OpenBLAS package that gets included in the
+  # the libopenblas-dev package by default. Usually this is OpenBLAS with pthreads.
+  #
+  # Note that libopenblas-dev must NOT be installed to ensure that R links to BLAS in a
+  # portable way, via the generic libblas.so provided by the libblas-dev package.
+  # This gets installed through the r-base build dependencies. If both libblas-dev and
+  # libopenblas-dev are present, R will prefer linking to OpenBLAS.
   && apt install -y curl libcurl4-openssl-dev libicu-dev libopenblas0-pthread libpcre2-dev libpcre3-dev unzip wget \
   && apt build-dep -y r-base