fix: decouple OLCF_AFAR_ROOT from AFAR_VERSION ARG in Dockerfile

ENV OLCF_AFAR_ROOT=/opt/${AFAR_VERSION} expanded to /opt/ in cpu/gpu
images because those builds supply no AFAR_VERSION. Introduce a
dedicated OLCF_AFAR_ROOT build-arg (default "") so cpu/gpu images get
an empty var and only the AMD build passes the real path.

Author: sbryngelson

.github/Dockerfile

@@ -8,6 +8,7 @@ ARG FC_COMPILER
 ARG COMPILER_PATH
 ARG COMPILER_LD_LIBRARY_PATH
 ARG AFAR_VERSION
+ARG OLCF_AFAR_ROOT=""
 
 ENV DEBIAN_FRONTEND=noninteractive
 ENV TZ=UTC
@@ -78,7 +79,7 @@ COPY ../ /opt/MFC
 ENV CC=${CC_COMPILER}
 ENV CXX=${CXX_COMPILER}
 ENV FC=${FC_COMPILER}
-ENV OLCF_AFAR_ROOT=/opt/${AFAR_VERSION}
+ENV OLCF_AFAR_ROOT=${OLCF_AFAR_ROOT}
 ENV PATH="${COMPILER_PATH}:/opt/mpich/bin:$PATH"
 ENV LD_LIBRARY_PATH="${COMPILER_LD_LIBRARY_PATH}:/opt/mpich/lib:${LD_LIBRARY_PATH:-}"
 

.github/workflows/docker.yml

@@ -145,6 +145,7 @@ jobs:
             BASE_IMAGE=${{ matrix.config.base_image }}
             TARGET=amd
             AFAR_VERSION=rocm-afar-8873-drop-22.2.0
+            OLCF_AFAR_ROOT=/opt/rocm-afar-8873-drop-22.2.0
             CC_COMPILER=gcc
             CXX_COMPILER=g++
             FC_COMPILER=/opt/rocm-afar-8873-drop-22.2.0/bin/amdflang