diff --git a/bin/tools/foamConfigurePaths b/bin/tools/foamConfigurePaths
index 03859f4ce7..11715dad27 100755
--- a/bin/tools/foamConfigurePaths
+++ b/bin/tools/foamConfigurePaths
@@ -7,7 +7,7 @@
 #    \\/     M anipulation  |
 #------------------------------------------------------------------------------
 #     Copyright (C) 2011-2016 OpenFOAM Foundation
-#     Copyright (C) 2016-2020 OpenCFD Ltd.
+#     Copyright (C) 2016-2021 OpenCFD Ltd.
 #------------------------------------------------------------------------------
 # License
 #     This file is part of OpenFOAM, distributed under GPL-3.0-or-later.
@@ -55,6 +55,8 @@ Equivalent options:
   -scotch-path          --scotchArchPath | -scotchArchPath
   -system-compiler      -system
   -third-compiler       -third
+  -openmpi-system       -sys-openmpi
+  -openmpi-third        -openmpi
 
 HELP_COMPAT
         exit 0 # A clean exit
@@ -89,10 +91,9 @@ Compiler
   mpc-VERSION         For ThirdParty gcc (mpc-system for system library)
 
 MPI
-  -mpi NAME           specify 'WM_MPLIB' type (eg, INTELMPI, etc)
-  -openmpi VER        use ThirdParty openmpi, with version for 'FOAM_MPI'
-  -openmpi-system     use system openmpi
-  -openmpi-third      use ThirdParty openmpi (using default version)
+  -mpi=NAME           Specify 'WM_MPLIB' type (eg, INTELMPI, etc)
+  -openmpi[=VER]      Use ThirdParty openmpi, with version for 'FOAM_MPI'
+  -sys-openmpi[=MAJ]  Use system openmpi, with specified major version
 
 Components versions (ThirdParty)
   -adios VER          specify 'adios2_version'
@@ -212,12 +213,13 @@ _inlineSed()
     # Local filename (for reporting)
     localFile="$(echo "$file" | sed -e "s#^$projectDir/##")"
 
-    grep -q "$regexp" "$file" && sed -i -e "$cmd" "$file" || { \
+    if grep -q "$regexp" "$file" && sed -i -e "$cmd" "$file"
+    then
+        [ -n "$msg" ] && echo "    $msg  ($localFile)"
+    else
         echo "Failed: ${msg:-replacement} in $localFile"
         return 1
-    }
-
-    [ -n "$msg" ] && echo "    $msg  ($localFile)"
+    fi
 
     return 0
 }
@@ -278,8 +280,8 @@ replaceEtc()
     local file="$1"
     shift
 
-    file=$(_foamEtc "$file")
-    replace $file "$@"
+    file="$(_foamEtc "$file")"
+    replace "$file" "$@"
 }
 
 
@@ -289,24 +291,36 @@ replaceEtcCsh()
     local file="$1"
     shift
 
-    file=$(_foamEtc "$file")
-    replaceCsh $file "$@"
+    file="$(_foamEtc "$file")"
+    replaceCsh "$file" "$@"
 }
 
 
 # Get the option's value (argument), or die on missing or empty argument
 # $1 option
 # $2 value
+
+# Returns values via optValue, nOptArgs variables!!
+optValue=""
+nOptArgs=0  # The number of args to shift
+
 getOptionValue()
 {
-    local value="$2"
-    [ -n "$value" ] || die "'$1' option requires an argument"
+    optValue="${1#*=}"
+    if [ "$optValue" = "$1" ]
+    then
+        # Eg, -option value
+        optValue="$2"
+        [ -n "$optValue" ] || die "'$1' option requires an argument"
+        nOptArgs=1
+    else
+        # Eg, -option=value
+        nOptArgs=0
+    fi
 
     # Remove any surrounding double quotes
-    value="${value%\"}"
-    value="${value#\"}"
-
-    echo "$value"
+    optValue="${optValue%\"}"
+    optValue="${optValue#\"}"
 }
 
 
@@ -366,7 +380,7 @@ removeCshMagic()
 
 #------------------------------------------------------------------------------
 
-unset adjusted optMpi
+unset adjusted
 # Parse options
 while [ "$#" -gt 0 ]
 do
@@ -420,26 +434,37 @@ CONFIG_CSH
         export FOAM_CONFIG_ETC="${1#*=}"
         ;;
 
-   -project-path)
+   -project-path=* | -project-path)
         # Replace WM_PROJECT_DIR=...
-        optionValue=$(getOptionValue "$@")
-        replaceEtc     bashrc  WM_PROJECT_DIR "\"$optionValue\""
-        replaceEtcCsh  cshrc   WM_PROJECT_DIR "\"$optionValue\""
+        getOptionValue "$@"
+        shift "${nOptArgs:-0}"
 
-        removeBashMagic $(_foamEtc bashrc)
-        removeCshMagic  $(_foamEtc cshrc)
+        if [ -n "$optValue" ]
+        then
+            replaceEtc     bashrc  WM_PROJECT_DIR "\"$optValue\""
+            replaceEtcCsh  cshrc   WM_PROJECT_DIR "\"$optValue\""
 
-        adjusted=true
-        shift
+            removeBashMagic "$(_foamEtc bashrc)"
+            removeCshMagic  "$(_foamEtc cshrc)"
+            adjusted=true
+        else
+            : "${adjusted:=empty}"
+        fi
         ;;
 
-   -version | -foamVersion | --projectVersion)
+   -version=* | -version | -foamVersion | --projectVersion)
         # Replace WM_PROJECT_VERSION=...
-        optionValue=$(getOptionValue "$@")
-        replaceEtc     bashrc  WM_PROJECT_VERSION "$optionValue"
-        replaceEtcCsh  cshrc   WM_PROJECT_VERSION "$optionValue"
-        adjusted=true
-        shift
+        getOptionValue "$@"
+        shift "${nOptArgs:-0}"
+
+        if [ -n "$optValue" ]
+        then
+            replaceEtc     bashrc  WM_PROJECT_VERSION "$optValue"
+            replaceEtcCsh  cshrc   WM_PROJECT_VERSION "$optValue"
+            adjusted=true
+        else
+            : "${adjusted:=empty}"
+        fi
         ;;
 
     -sp | -SP | -float32)
@@ -465,131 +490,168 @@ CONFIG_CSH
 
     -int32 | -int64)
         # Replace WM_LABEL_SIZE=...
-        optionValue="${1#-int}"
-        replaceEtc     bashrc  WM_LABEL_SIZE "$optionValue"
-        replaceEtcCsh  cshrc   WM_LABEL_SIZE "$optionValue"
+        optValue="${1#-int}"
+        replaceEtc     bashrc  WM_LABEL_SIZE "$optValue"
+        replaceEtcCsh  cshrc   WM_LABEL_SIZE "$optValue"
         adjusted=true
         ;;
 
 
 ## Compiler ##
 
-    -clang)
+    -clang=* | -clang)
         # Replace default_clang_version=...
-        optionValue=$(getOptionValue "$@")
-        replaceEtc  config.sh/compiler   default_clang_version "$optionValue"
-        replaceEtc  config.csh/compiler  default_clang_version "$optionValue"
-        adjusted=true
-        shift
+        getOptionValue "$@"
+        shift "${nOptArgs:-0}"
+
+        if [ -n "$optValue" ]
+        then
+            replaceEtc  config.sh/compiler   default_clang_version "$optValue"
+            replaceEtc  config.csh/compiler  default_clang_version "$optValue"
+            adjusted=true
+        else
+            : "${adjusted:=empty}"
+        fi
         ;;
 
-    -gcc)
+    -gcc=* | -gcc)
         # Replace default_gcc_version=...
-        optionValue=$(getOptionValue "$@")
-        replaceEtc  config.sh/compiler   default_gcc_version "$optionValue"
-        replaceEtc  config.csh/compiler  default_gcc_version "$optionValue"
-        adjusted=true
-        shift
+        getOptionValue "$@"
+        shift "${nOptArgs:-0}"
+
+        if [ -n "$optValue" ]
+        then
+            replaceEtc  config.sh/compiler   default_gcc_version "$optValue"
+            replaceEtc  config.csh/compiler  default_gcc_version "$optValue"
+            adjusted=true
+        else
+            : "${adjusted:=empty}"
+        fi
         ;;
 
     -system-compiler | -system)
         # Replace WM_COMPILER_TYPE=... and WM_COMPILER=...
-        optionValue=$(getOptionValue "$@")
-        replaceEtc  bashrc  \
-            WM_COMPILER_TYPE system \
-            WM_COMPILER "$optionValue"
-        replaceEtcCsh  cshrc \
-            WM_COMPILER_TYPE system \
-            WM_COMPILER "$optionValue"
-        adjusted=true
-        shift
+        getOptionValue "$@"
+        shift "${nOptArgs:-0}"
+
+        if [ -n "$optValue" ]
+        then
+            replaceEtc  bashrc  \
+                WM_COMPILER_TYPE system \
+                WM_COMPILER "$optValue"
+            replaceEtcCsh  cshrc \
+                WM_COMPILER_TYPE system \
+                WM_COMPILER "$optValue"
+            adjusted=true
+        else
+            : "${adjusted:=empty}"
+        fi
         ;;
 
     -third-compiler | -third | -ThirdParty)
         # Replace WM_COMPILER_TYPE=... and WM_COMPILER=...
-        optionValue=$(getOptionValue "$@")
-        replaceEtc  bashrc  \
-            WM_COMPILER_TYPE ThirdParty \
-            WM_COMPILER "$optionValue"
-        replaceEtcCsh  cshrc  \
-            WM_COMPILER_TYPE ThirdParty \
-            WM_COMPILER "$optionValue"
-        adjusted=true
-        shift
+        getOptionValue "$@"
+        shift "${nOptArgs:-0}"
+
+        if [ -n "$optValue" ]
+        then
+            replaceEtc  bashrc  \
+                WM_COMPILER_TYPE ThirdParty \
+                WM_COMPILER "$optValue"
+            replaceEtcCsh  cshrc  \
+                WM_COMPILER_TYPE ThirdParty \
+                WM_COMPILER "$optValue"
+            adjusted=true
+        else
+            : "${adjusted:=empty}"
+        fi
         ;;
 
     gmp-[4-9]* | gmp-system)
         # gcc-related package
-        replaceEtc  config.sh/compiler   default_gmp_version "$1"
-        replaceEtc  config.csh/compiler  default_gmp_version "$1"
+        optValue="${1#-}"
+        replaceEtc  config.sh/compiler   default_gmp_version "$optValue"
+        replaceEtc  config.csh/compiler  default_gmp_version "$optValue"
         adjusted=true
         ;;
 
     mpfr-[2-9]* | mpfr-system)
         # gcc-related package
-        replaceEtc  config.sh/compiler   default_mpfr_version "$1"
-        replaceEtc  config.csh/compiler  default_mpfr_version "$1"
+        optValue="${1#-}"
+        replaceEtc  config.sh/compiler   default_mpfr_version "$optValue"
+        replaceEtc  config.csh/compiler  default_mpfr_version "$optValue"
         adjusted=true
         ;;
 
     mpc-[0-9]* | mpc-system)
         # gcc-related package
-        replaceEtc  config.sh/compiler   default_mpc_version "$1"
-        replaceEtc  config.csh/compiler  default_mpc_version "$1"
+        optValue="${1#-}"
+        replaceEtc  config.sh/compiler   default_mpc_version "$optValue"
+        replaceEtc  config.csh/compiler  default_mpc_version "$optValue"
         adjusted=true
         ;;
 
 
 ## MPI ##
 
-    -mpi)
+    -mpi=* | -mpi)
         # Explicitly set WM_MPLIB=...
-        optionValue=$(getOptionValue "$@")
-        replaceEtc     bashrc  WM_MPLIB "$optionValue"
-        replaceEtcCsh  cshrc   WM_MPLIB "$optionValue"
-        optMpi=system
-        adjusted=true
-        shift
+        getOptionValue "$@"
+        shift "${nOptArgs:-0}"
+
+        if [ -n "$optValue" ]
+        then
+            replaceEtc     bashrc  WM_MPLIB "$optValue"
+            replaceEtcCsh  cshrc   WM_MPLIB "$optValue"
+            adjusted=true
+        else
+            : "${adjusted:=empty}"
+        fi
         ;;
 
-    -openmpi)
-        # Replace FOAM_MPI=openmpi-<digits>.. and set to use third-party
-        #  The edit is slightly fragile, but works
-        expected="openmpi-[1-9][.0-9]*"
-        optMpi=$(getOptionValue "$@")
-
-        _matches "$optMpi" "$expected" || \
-            die "'$1' has bad value: '$optMpi'"
-
-        _inlineSed  $(_foamEtc config.sh/mpi) \
-            "FOAM_MPI=$expected" \
-            "FOAM_MPI=$optMpi" \
-            "Replaced 'FOAM_MPI=$expected' by 'FOAM_MPI=$optMpi'"
-
-        _inlineSed  $(_foamEtc config.csh/mpi) \
-            "FOAM_MPI $expected" \
-            "FOAM_MPI $optMpi" \
-            "Replaced 'FOAM_MPI $expected' by 'FOAM_MPI $optMpi'"
-
-        replaceEtc     bashrc  WM_MPLIB OPENMPI
-        replaceEtcCsh  cshrc   WM_MPLIB OPENMPI
-        adjusted=true
-        shift
-        ;;
-
-    -openmpi-system)
+    -sys-openmpi=* | -sys-openmpi | -openmpi-system)
+        optValue="$(echo "$1" | sed -ne 's/^.*mpi=\([1-9][0-9]*\).*/\1/p')"
         # Explicitly set WM_MPLIB=SYSTEMOPENMPI
-        replaceEtc     bashrc  WM_MPLIB SYSTEMOPENMPI
-        replaceEtcCsh  cshrc   WM_MPLIB SYSTEMOPENMPI
-        optMpi=system
-        adjusted=true
+        if [ -n "$optValue" ]
+        then
+            replaceEtc     bashrc  WM_MPLIB SYSTEMOPENMPI"$optValue"
+            replaceEtcCsh  cshrc   WM_MPLIB SYSTEMOPENMPI"$optValue"
+            adjusted=true
+        else
+            : "${adjusted:=empty}"
+        fi
         ;;
 
-    -openmpi-third)
-        # Explicitly set WM_MPLIB=OPENMPI, using default setting for openmpi
+    -openmpi=* | -openmpi | -openmpi-third)
+        # Explicitly set WM_MPLIB=OPENMPI
+        # - use default setting for openmpi, or
+        #  replace FOAM_MPI=openmpi-<digits>..
+        #  The edit is slightly fragile, but works
+
+        expected="openmpi-[1-9][.0-9]*"
+        optValue="$(echo "$1" | sed -ne 's/^.*mpi=//p')"
+        if [ -n "$optValue" ]
+        then
+             if [ "${optValue#openmpi-}" = "$optValue" ]
+             then
+                 optValue="openmpi-$optValue"
+             fi
+
+            _matches "$optValue" "$expected" || \
+                die "'${1%=*}' has bad value: '$optValue'"
+
+            _inlineSed  "$(_foamEtc config.sh/mpi)" \
+                "FOAM_MPI=$expected" \
+                "FOAM_MPI=$optValue" \
+                "Replaced 'FOAM_MPI=$expected' by 'FOAM_MPI=$optValue'"
+
+            _inlineSed  "$(_foamEtc config.csh/mpi)" \
+                "FOAM_MPI=$expected" \
+                "FOAM_MPI=$optValue" \
+                "Replaced 'FOAM_MPI $expected' by 'FOAM_MPI $optValue'"
+        fi
         replaceEtc     bashrc  WM_MPLIB OPENMPI
         replaceEtcCsh  cshrc   WM_MPLIB OPENMPI
-        optMpi=third
         adjusted=true
         ;;
 
@@ -598,146 +660,242 @@ CONFIG_CSH
 
     -adios | -adios2)
         # Replace adios2_version=...
-        optionValue=$(getOptionValue "$@")
-        replaceEtc  config.sh/adios2   adios2_version "$optionValue"
-        replaceEtc  config.csh/adios2  adios2_version "$optionValue"
-        adjusted=true
-        shift
+        getOptionValue "$@"
+        shift "${nOptArgs:-0}"
+
+        if [ -n "$optValue" ]
+        then
+            replaceEtc  config.sh/adios2   adios2_version "$optValue"
+            replaceEtc  config.csh/adios2  adios2_version "$optValue"
+            adjusted=true
+        else
+            : "${adjusted:=empty}"
+        fi
         ;;
 
     -adios-path | -adios2-path)
         # Replace ADIOS2_ARCH_PATH=...
-        optionValue=$(getOptionValue "$@")
-        replaceEtc     config.sh/adios2   ADIOS2_ARCH_PATH "\"$optionValue\""
-        replaceEtcCsh  config.csh/adios2  ADIOS2_ARCH_PATH "\"$optionValue\""
-        adjusted=true
-        shift
+        getOptionValue "$@"
+        shift "${nOptArgs:-0}"
+
+        if [ -n "$optValue" ]
+        then
+            replaceEtc     config.sh/adios2   ADIOS2_ARCH_PATH "\"$optValue\""
+            replaceEtcCsh  config.csh/adios2  ADIOS2_ARCH_PATH "\"$optValue\""
+            adjusted=true
+        else
+            : "${adjusted:=empty}"
+        fi
         ;;
 
     -boost)
         # Replace boost_version=...  (config is cgal or CGAL)
-        optionValue=$(getOptionValue "$@")
+        getOptionValue "$@"
+        shift "${nOptArgs:-0}"
+
         cfgName=cgal; _foamEtc -q config.sh/"$cfgName" || cfgName=CGAL
-        replaceEtc  config.sh/"$cfgName"   boost_version "$optionValue"
-        replaceEtc  config.csh/"$cfgName"  boost_version "$optionValue"
-        adjusted=true
-        shift
+        if [ -n "$optValue" ]
+        then
+            replaceEtc  config.sh/"$cfgName"   boost_version "$optValue"
+            replaceEtc  config.csh/"$cfgName"  boost_version "$optValue"
+            adjusted=true
+        else
+            : "${adjusted:=empty}"
+        fi
         ;;
 
     -boost-path)
         # Replace BOOST_ARCH_PATH=...  (config is cgal or CGAL)
-        optionValue=$(getOptionValue "$@")
+        getOptionValue "$@"
+        shift "${nOptArgs:-0}"
+
         cfgName=cgal; _foamEtc -q config.sh/"$cfgName" || cfgName=CGAL
-        replaceEtc  config.sh/"$cfgName"   BOOST_ARCH_PATH "\"$optionValue\""
-        replaceEtc  config.csh/"$cfgName"  BOOST_ARCH_PATH "\"$optionValue\""
-        adjusted=true
-        shift
+        if [ -n "$optValue" ]
+        then
+            replaceEtc  config.sh/"$cfgName"   BOOST_ARCH_PATH "\"$optValue\""
+            replaceEtc  config.csh/"$cfgName"  BOOST_ARCH_PATH "\"$optValue\""
+            adjusted=true
+        else
+            : "${adjusted:=empty}"
+        fi
         ;;
 
     -cgal)
         # Replace cgal_version=...  (config is cgal or CGAL)
-        optionValue=$(getOptionValue "$@")
+        getOptionValue "$@"
+        shift "${nOptArgs:-0}"
+
         cfgName=cgal; _foamEtc -q config.sh/"$cfgName" || cfgName=CGAL
-        replaceEtc  config.sh/"$cfgName"   cgal_version "$optionValue"
-        replaceEtc  config.csh/"$cfgName"  cgal_version "$optionValue"
-        adjusted=true
-        shift
+        if [ -n "$optValue" ]
+        then
+            replaceEtc  config.sh/"$cfgName"   cgal_version "$optValue"
+            replaceEtc  config.csh/"$cfgName"  cgal_version "$optValue"
+            adjusted=true
+        else
+            : "${adjusted:=empty}"
+        fi
         ;;
 
     -cgal-path)
         # Replace CGAL_ARCH_PATH=...  (config is cgal or CGAL)
-        optionValue=$(getOptionValue "$@")
+        getOptionValue "$@"
+        shift "${nOptArgs:-0}"
+
         cfgName=cgal; _foamEtc -q config.sh/"$cfgName" || cfgName=CGAL
-        replaceEtc     config.sh/"$cfgName"   CGAL_ARCH_PATH "$optionValue"
-        replaceEtcCsh  config.csh/"$cfgName"  CGAL_ARCH_PATH "$optionValue"
-        adjusted=true
-        shift
+        if [ -n "$optValue" ]
+        then
+            replaceEtc     config.sh/"$cfgName"   CGAL_ARCH_PATH "$optValue"
+            replaceEtcCsh  config.csh/"$cfgName"  CGAL_ARCH_PATH "$optValue"
+            adjusted=true
+        else
+            : "${adjusted:=empty}"
+        fi
         ;;
 
     -fftw)
         # Replace fftw_version=...
-        optionValue=$(getOptionValue "$@")
+        getOptionValue "$@"
+        shift "${nOptArgs:-0}"
+
         # config.sh/fftw or config.sh/FFTW
         cfgName=fftw; _foamEtc -q config.sh/"$cfgName" || cfgName=FFTW
-        replaceEtc  config.sh/"$cfgName"   fftw_version "$optionValue"
-        replaceEtc  config.csh/"$cfgName"  fftw_version "$optionValue"
-        adjusted=true
-        shift
+        if [ -n "$optValue" ]
+        then
+            replaceEtc  config.sh/"$cfgName"   fftw_version "$optValue"
+            replaceEtc  config.csh/"$cfgName"  fftw_version "$optValue"
+            adjusted=true
+        else
+            : "${adjusted:=empty}"
+        fi
         ;;
 
     -fftw-path)
         # Replace FFTW_ARCH_PATH=...
-        optionValue=$(getOptionValue "$@")
+        getOptionValue "$@"
+        shift "${nOptArgs:-0}"
+
         # config.sh/fftw or config.sh/FFTW
         cfgName=fftw; _foamEtc -q config.sh/"$cfgName" || cfgName=FFTW
-        replaceEtc     config.sh/"$cfgName"  FFTW_ARCH_PATH "\"$optionValue\""
-        replaceEtcCsh  config.csh/"$cfgName" FFTW_ARCH_PATH "\"$optionValue\""
-        adjusted=true
-        shift
+        if [ -n "$optValue" ]
+        then
+            replaceEtc     config.sh/"$cfgName"  FFTW_ARCH_PATH "\"$optValue\""
+            replaceEtcCsh  config.csh/"$cfgName" FFTW_ARCH_PATH "\"$optValue\""
+            adjusted=true
+        else
+            : "${adjusted:=empty}"
+        fi
         ;;
 
     -cmake)
         # Replace cmake_version=...
-        optionValue=$(getOptionValue "$@")
-        replaceEtc  config.sh/cmake   cmake_version "$optionValue"
-        adjusted=true
-        shift
+        getOptionValue "$@"
+        shift "${nOptArgs:-0}"
+
+        if [ -n "$optValue" ]
+        then
+            replaceEtc  config.sh/cmake   cmake_version "$optValue"
+            adjusted=true
+        else
+            : "${adjusted:=empty}"
+        fi
         ;;
 
     -cmake-path)
         # Replace CMAKE_ARCH_PATH=...
-        optionValue=$(getOptionValue "$@")
-        replaceEtc  config.sh/cmake   CMAKE_ARCH_PATH "$optionValue"
-        adjusted=true
-        shift
+        getOptionValue "$@"
+        shift "${nOptArgs:-0}"
+
+        if [ -n "$optValue" ]
+        then
+            replaceEtc  config.sh/cmake   CMAKE_ARCH_PATH "$optValue"
+            adjusted=true
+        else
+            : "${adjusted:=empty}"
+        fi
         ;;
 
     -kahip)
         # Replace KAHIP_VERSION=...
-        optionValue=$(getOptionValue "$@")
-        replaceEtc  config.sh/kahip  KAHIP_VERSION "$optionValue"
-        adjusted=true
-        shift
+        getOptionValue "$@"
+        shift "${nOptArgs:-0}"
+
+        if [ -n "$optValue" ]
+        then
+            replaceEtc  config.sh/kahip  KAHIP_VERSION "$optValue"
+            adjusted=true
+        else
+            : "${adjusted:=empty}"
+        fi
         ;;
 
     -kahip-path)
         # Replace KAHIP_ARCH_PATH=...
-        optionValue=$(getOptionValue "$@")
-        replaceEtc  config.sh/kahip  KAHIP_ARCH_PATH "\"$optionValue\""
-        adjusted=true
-        shift
+        getOptionValue "$@"
+        shift "${nOptArgs:-0}"
+
+        if [ -n "$optValue" ]
+        then
+            replaceEtc  config.sh/kahip  KAHIP_ARCH_PATH "\"$optValue\""
+            adjusted=true
+        else
+            : "${adjusted:=empty}"
+        fi
         ;;
 
     -metis)
         # Replace METIS_VERSION=...
-        optionValue=$(getOptionValue "$@")
-        replaceEtc  config.sh/metis  METIS_VERSION "$optionValue"
-        adjusted=true
-        shift
+        getOptionValue "$@"
+        shift "${nOptArgs:-0}"
+
+        if [ -n "$optValue" ]
+        then
+            replaceEtc  config.sh/metis  METIS_VERSION "$optValue"
+            adjusted=true
+        else
+            : "${adjusted:=empty}"
+        fi
         ;;
 
     -metis-path)
         # Replace METIS_ARCH_PATH=...
-        optionValue=$(getOptionValue "$@")
-        replaceEtc  config.sh/metis  METIS_ARCH_PATH "\"$optionValue\""
-        adjusted=true
-        shift
+        getOptionValue "$@"
+        shift "${nOptArgs:-0}"
+
+        if [ -n "$optValue" ]
+        then
+            replaceEtc  config.sh/metis  METIS_ARCH_PATH "\"$optValue\""
+            adjusted=true
+        else
+            : "${adjusted:=empty}"
+        fi
         ;;
 
     -scotch | -scotchVersion | --scotchVersion)
         # Replace SCOTCH_VERSION=...
-        optionValue=$(getOptionValue "$@")
-        replaceEtc  config.sh/scotch  SCOTCH_VERSION "$optionValue"
-        adjusted=true
-        shift
+        getOptionValue "$@"
+        shift "${nOptArgs:-0}"
+
+        if [ -n "$optValue" ]
+        then
+            replaceEtc  config.sh/scotch  SCOTCH_VERSION "$optValue"
+            adjusted=true
+        else
+            : "${adjusted:=empty}"
+        fi
         ;;
 
     -scotch-path | -scotchArchPath | --scotchArchPath)
         # Replace SCOTCH_ARCH_PATH=...
-        optionValue=$(getOptionValue "$@")
-        replaceEtc  config.sh/scotch  SCOTCH_ARCH_PATH "\"$optionValue\""
-        adjusted=true
-        shift
+        getOptionValue "$@"
+        shift "${nOptArgs:-0}"
+
+        if [ -n "$optValue" ]
+        then
+            replaceEtc  config.sh/scotch  SCOTCH_ARCH_PATH "\"$optValue\""
+            adjusted=true
+        else
+            : "${adjusted:=empty}"
+        fi
         ;;
 
 
@@ -746,107 +904,156 @@ CONFIG_CSH
     -paraview | -paraviewVersion | --paraviewVersion)
         # Replace ParaView_VERSION=...
         expected="[5-9][.0-9]*"  # but also accept system
-        optionValue=$(getOptionValue "$@")
-        _matches "$optionValue" "$expected" || \
-            [ "$optionValue" != "${optionValue%system}" ] || \
-            die "'$1' has bad value: '$optionValue'"
-        replaceEtc  config.sh/paraview   ParaView_VERSION "$optionValue"
-        replaceEtc  config.csh/paraview  ParaView_VERSION "$optionValue"
-        adjusted=true
-        shift
+        getOptionValue "$@"
+        _matches "$optValue" "$expected" || \
+            [ "$optValue" != "${optValue%system}" ] || \
+            die "'${1%=*}' has bad value: '$optValue'"
+
+        shift "${nOptArgs:-0}"
+        if [ -n "$optValue" ]
+        then
+            replaceEtc  config.sh/paraview   ParaView_VERSION "$optValue"
+            replaceEtc  config.csh/paraview  ParaView_VERSION "$optValue"
+            adjusted=true
+        else
+            : "${adjusted:=empty}"
+        fi
         ;;
 
     -paraview-qt)
         # Replace ParaView_QT=...
-        optionValue=$(getOptionValue "$@")
-        replaceEtc  config.sh/paraview   ParaView_QT "$optionValue"
-        replaceEtc  config.csh/paraview  ParaView_QT "$optionValue"
-        adjusted=true
-        shift
+        getOptionValue "$@"
+        shift "${nOptArgs:-0}"
+
+        if [ -n "$optValue" ]
+        then
+            replaceEtc  config.sh/paraview   ParaView_QT "$optValue"
+            replaceEtc  config.csh/paraview  ParaView_QT "$optValue"
+            adjusted=true
+        else
+            : "${adjusted:=empty}"
+        fi
         ;;
 
     -paraview-path | -paraviewInstall | --paraviewInstall)
         # Replace ParaView_DIR=...
-        optionValue=$(getOptionValue "$@")
-        replaceEtc     config.sh/paraview   ParaView_DIR \""$optionValue\""
-        replaceEtcCsh  config.csh/paraview  ParaView_DIR \""$optionValue\""
-        adjusted=true
-        shift
+        getOptionValue "$@"
+        shift "${nOptArgs:-0}"
+
+        if [ -n "$optValue" ]
+        then
+            replaceEtc     config.sh/paraview   ParaView_DIR \""$optValue\""
+            replaceEtcCsh  config.csh/paraview  ParaView_DIR \""$optValue\""
+            adjusted=true
+        else
+            : "${adjusted:=empty}"
+        fi
         ;;
 
     -llvm)
         # Replace mesa_llvm=...
-        optionValue=$(getOptionValue "$@")
-        replaceEtc  config.sh/vtk   mesa_llvm "$optionValue"
-        replaceEtc  config.csh/vtk  mesa_llvm "$optionValue"
-        adjusted=true
-        shift
+        getOptionValue "$@"
+        shift "${nOptArgs:-0}"
+
+        if [ -n "$optValue" ]
+        then
+            replaceEtc  config.sh/vtk   mesa_llvm "$optValue"
+            replaceEtc  config.csh/vtk  mesa_llvm "$optValue"
+            adjusted=true
+        else
+            : "${adjusted:=empty}"
+        fi
         ;;
 
     -mesa)
         # Replace mesa_version=...
-        optionValue=$(getOptionValue "$@")
-        replaceEtc  config.sh/vtk   mesa_version "$optionValue"
-        replaceEtc  config.csh/vtk  mesa_version "$optionValue"
-        adjusted=true
-        shift
+        getOptionValue "$@"
+        shift "${nOptArgs:-0}"
+
+        if [ -n "$optValue" ]
+        then
+            replaceEtc  config.sh/vtk   mesa_version "$optValue"
+            replaceEtc  config.csh/vtk  mesa_version "$optValue"
+            adjusted=true
+        else
+            : "${adjusted:=empty}"
+        fi
         ;;
 
     -vtk)
         # Replace vtk_version=...
-        optionValue=$(getOptionValue "$@")
-        replaceEtc  config.sh/vtk   vtk_version "$optionValue"
-        replaceEtc  config.csh/vtk  vtk_version "$optionValue"
-        adjusted=true
-        shift
+        getOptionValue "$@"
+        shift "${nOptArgs:-0}"
+
+        if [ -n "$optValue" ]
+        then
+            replaceEtc  config.sh/vtk   vtk_version "$optValue"
+            replaceEtc  config.csh/vtk  vtk_version "$optValue"
+            adjusted=true
+        else
+            : "${adjusted:=empty}"
+        fi
         ;;
 
     -llvm-path)
         # Replace LLVM_ARCH_PATH=...
-        optionValue=$(getOptionValue "$@")
-        replaceEtc     config.sh/vtk   LLVM_ARCH_PATH \""$optionValue\""
-        replaceEtcCsh  config.csh/vtk  LLVM_ARCH_PATH \""$optionValue\""
-        adjusted=true
-        shift
+        getOptionValue "$@"
+        shift "${nOptArgs:-0}"
+
+        if [ -n "$optValue" ]
+        then
+            replaceEtc     config.sh/vtk   LLVM_ARCH_PATH \""$optValue\""
+            replaceEtcCsh  config.csh/vtk  LLVM_ARCH_PATH \""$optValue\""
+            adjusted=true
+        else
+            : "${adjusted:=empty}"
+        fi
         ;;
 
     -mesa-path)
         # Replace MESA_ARCH_PATH...
-        optionValue=$(getOptionValue "$@")
-        replaceEtc     config.sh/vtk   MESA_ARCH_PATH \""$optionValue\""
-        replaceEtcCsh  config.csh/vtk  MESA_ARCH_PATH \""$optionValue\""
-        adjusted=true
-        shift
+        getOptionValue "$@"
+        shift "${nOptArgs:-0}"
+
+        if [ -n "$optValue" ]
+        then
+            replaceEtc     config.sh/vtk   MESA_ARCH_PATH \""$optValue\""
+            replaceEtcCsh  config.csh/vtk  MESA_ARCH_PATH \""$optValue\""
+            adjusted=true
+        else
+            : "${adjusted:=empty}"
+        fi
         ;;
 
     -vtk-path)
         # Replace VTK_DIR...
-        optionValue=$(getOptionValue "$@")
-        replaceEtc     config.sh/vtk   VTK_DIR \""$optionValue\""
-        replaceEtcCsh  config.csh/vtk  VTK_DIR \""$optionValue\""
-        adjusted=true
-        shift
+        getOptionValue "$@"
+        shift "${nOptArgs:-0}"
+
+        if [ -n "$optValue" ]
+        then
+            replaceEtc     config.sh/vtk   VTK_DIR \""$optValue\""
+            replaceEtcCsh  config.csh/vtk  VTK_DIR \""$optValue\""
+            adjusted=true
+        else
+            : "${adjusted:=empty}"
+        fi
         ;;
 
 
 ## Misc ##
 
+    # Obsolete flags
     -sigfpe | -no-sigfpe)
         echo "Enable/disable FOAM_SIGFPE now via controlDict" 1>&2
         ;;
 
-    -archOption | --archOption)
-        # Replace WM_ARCH_OPTION=...
-        optionValue=$(getOptionValue "$@")
-        echo "Ignoring $1 option: no longer supported" 1>&2
-        shift
-        ;;
-
+    # Obsolete options
+    -archOption | --archOption | \
     -foamInstall | --foamInstall | -projectName | --projectName)
-        # Removed for 1812
-        optionValue=$(getOptionValue "$@")
-        echo "Ignoring $1 option: obsolete" 1>&2
-        shift
+        echo "Ignoring obsolete option: $1" 1>&2
+        getOptionValue "$@"
+        shift "${nOptArgs:-0}"
         ;;
 
     *)