diff --git a/bin/tools/foamConfigurePaths b/bin/tools/foamConfigurePaths
index f0536bd694a462f1b2fa35f69b7862fdbbc92823..acaa5455aad742257aa35132712b63a27ddddfbf 100644
--- a/bin/tools/foamConfigurePaths
+++ b/bin/tools/foamConfigurePaths
@@ -50,15 +50,30 @@ USAGE
 # inlineSed <file> <sedCommand> <description>
 _inlineSed()
 {
-    backup=`tempfile`
+    [ -f "$1" ] || {
+        echo "Missing file: $1"
+        exit 1
+    }
+
+    backup="temp.$$"
     cp $1 $backup
     sed -i -e "$2" $1
-    cmp --quiet $1 $backup && usage "Failed : $3"
+
+    if cmp $1 $backup > /dev/null 2>&1
+    then
+        echo "Failed: $3 in $1"
+        rm $backup 2>/dev/null
+        exit 1
+    else
+        echo "Okay: $3 in $1"
+        rm $backup 2>/dev/null
+    fi
+
     return 0
 }
 
 
-[ -f etc/bashrc -a -f etc/settings.sh ] || usage "Please run from top-level directory of installation"
+[ -f etc/bashrc ] || usage "Please run from top-level directory of installation"
 
 unset foamInstall projectName archOption paraviewInstall
 
@@ -66,39 +81,43 @@ unset foamInstall projectName archOption paraviewInstall
 while [ "$#" -gt 0 ]
 do
     case "$1" in
-    -h | --help)
+    -h | -help | --help)
         usage
         ;;
-    --foamInstall)
+    -foamInstall | --foamInstall)
         [ "$#" -ge 2 ] || usage "'$1' option requires an argument"
         foamInstall="$2"
+        # replace foamInstall=...
         _inlineSed \
             etc/bashrc \
             '/^[^#]/s@foamInstall=.*@foamInstall='"$foamInstall@" \
             "Replacing foamInstall setting by '$foamInstall'"
         shift 2
         ;;
-   --projectName)
+   -projectName | --projectName)
         [ "$#" -ge 2 ] || usage "'$1' option requires an argument"
         projectName="$2"
+        # replace WM_PROJECT_DIR=...
         _inlineSed \
             etc/bashrc \
             '/^[^#]/s@WM_PROJECT_DIR=.*@WM_PROJECT_DIR=$WM_PROJECT_INST_DIR/'"$projectName@" \
             "Replacing WM_PROJECT_DIR setting by '$projectName'"
         shift 2
         ;;
-    --archOption)
+    -archOption | --archOption)
         [ "$#" -ge 2 ] || usage "'$1' option requires an argument"
         archOption="$2"
+        # replace WM_ARCH_OPTION=...
         _inlineSed \
             etc/bashrc \
-            '/^[^#]/s@: ${WM_ARCH_OPTION:=64}@WM_ARCH_OPTION='"$archOption@" \
+            '/^[^#]/s@WM_ARCH_OPTION=.*@WM_ARCH_OPTION='"$archOption@" \
              "Replacing WM_ARCH_OPTION setting by '$archOption'"
         shift 2
         ;;
-    --paraviewInstall)
+    -paraviewInstall | --paraviewInstall)
         [ "$#" -ge 2 ] || usage "'$1' option requires an argument"
         paraviewInstall="$2"
+        # replace ParaView_DIR=...
         _inlineSed \
             etc/apps/paraview3/bashrc \
             '/^[^#]/s@ParaView_DIR=.*@ParaView_DIR='"$paraviewInstall@" \
@@ -116,15 +135,16 @@ done
 #echo "Replacing WM_PROJECT setting by '$projectName'"
 #sed -i -e 's@WM_PROJECT=.*@WM_PROJECT='"$projectName@" etc/bashrc
 
-# Replace the WM_MPLIB always
+# Set WM_MPLIB=SYSTEMOPENMPI always
 _inlineSed \
     etc/bashrc \
-    '/^[^#]/s@: ${WM_MPLIB:=.*}@WM_MPLIB=SYSTEMOPENMPI@' \
+    '/^[^#]/s@export WM_MPLIB=.*@export WM_MPLIB=SYSTEMOPENMPI@' \
     "Replacing WM_MPLIB setting by 'SYSTEMOPENMPI'"
-# Replace the foamCompiler always
+
+# set foamCompiler=system always
 _inlineSed \
-    etc/settings.sh \
-    '/^[^#]/s@: ${foamCompiler:=.*}@foamCompiler=system@' \
+    etc/bashrc \
+    '/^[^#]/s@foamCompiler=.*@foamCompiler=system@' \
     "Replacing foamCompiler setting by 'system'"
 
 #------------------------------------------------------------------------------
diff --git a/etc/apps/paraview3/bashrc b/etc/apps/paraview3/bashrc
index 5487d2e8db113fc891775931d428be6c07824daf..0be7e237196778ca07e577bc4c9d824360119f56 100644
--- a/etc/apps/paraview3/bashrc
+++ b/etc/apps/paraview3/bashrc
@@ -26,7 +26,7 @@
 #
 # Description
 #     Setup file for paraview-3.x
-#     Sourced from OpenFOAM-*/etc/bashrc or from foamPV alias
+#     Sourced from OpenFOAM-<VERSION>/etc/bashrc or from foamPV alias
 #
 # Note
 #     The env. variables 'ParaView_DIR' and 'ParaView_MAJOR'
@@ -51,8 +51,14 @@ done
 
 
 # set VERSION and MAJOR (version) variables
-ParaView_VERSION=3.8.0
-ParaView_MAJOR=unknown
+if [ -z "$ParaView_VERSION" ]
+then
+    ParaView_VERSION=3.8.0
+    ParaView_MAJOR=unknown
+    echo "Warning in app/paraview3/bashrc:" 1>&2
+    echo "    ParaView_VERSION not set, using '$ParaView_VERSION'" 1>&2
+fi
+[ -n "$ParaView_MAJOR" ] || ParaView_MAJOR=unknown
 
 # if needed, set MAJOR version to correspond to VERSION
 # ParaView_MAJOR is "<digits>.<digits>" from ParaView_VERSION
diff --git a/etc/apps/paraview3/cshrc b/etc/apps/paraview3/cshrc
index 850eb78d27983bbbef90f55332c185c60fedb5f4..dc52735480cfa8bea5284e3155697da67a922741 100644
--- a/etc/apps/paraview3/cshrc
+++ b/etc/apps/paraview3/cshrc
@@ -26,7 +26,7 @@
 #
 # Description
 #     Setup file for paraview-3.x
-#     Sourced from OpenFOAM-*/etc/cshrc or from foamPV alias
+#     Sourced from OpenFOAM-<VERSION>/etc/cshrc or from foamPV alias
 #
 # Note
 #     The env. variables 'ParaView_DIR' and 'ParaView_MAJOR'
@@ -49,8 +49,14 @@ foreach cmake ( cmake-2.8.3 cmake-2.8.1 cmake-2.8.0 cmake-2.6.4 )
 end
 
 # set VERSION and MAJOR (version) variables
-setenv ParaView_VERSION 3.8.0
-setenv ParaView_MAJOR unknown
+if ( ! $?ParaView_VERSION )
+then
+    setenv ParaView_VERSION 3.8.0
+    setenv ParaView_MAJOR unknown
+    echo "Warning in app/paraview3/cshrc:"
+    echo "    ParaView_VERSION not set, using '$ParaView_VERSION'"
+fi
+if ( ! $?ParaView_MAJOR ) setenv ParaView_MAJOR unknown
 
 # if needed, set MAJOR version to correspond to VERSION
 # ParaView_MAJOR is "<digits>.<digits>" from ParaView_VERSION
diff --git a/etc/bashrc b/etc/bashrc
index 2b0e3d0be71897e8f825e5d6dcb0a40f7a6b8f05..c95a7951bba68b7f91627faf5a9840a511e6ba7e 100644
--- a/etc/bashrc
+++ b/etc/bashrc
@@ -35,24 +35,73 @@ export WM_PROJECT=OpenFOAM
 export WM_PROJECT_VERSION=dev
 
 ################################################################################
-# USER EDITABLE PART. Note changes made here may be lost with the next upgrade
+# USER EDITABLE PART: Changes made here may be lost with the next upgrade
 #
 # either set $FOAM_INST_DIR before sourcing this file or set
-#    $foamInstall below to where OpenFOAM is installed
+# 'foamInstall' below to where OpenFOAM is installed
 #
 # Location of the OpenFOAM installation
 # ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 foamInstall=$HOME/$WM_PROJECT
 # foamInstall=~$WM_PROJECT
-# foamInstall=/usr/local/$WM_PROJECT
 # foamInstall=/opt/$WM_PROJECT
+# foamInstall=/usr/local/$WM_PROJECT
 #
 # END OF (NORMAL) USER EDITABLE PART
 ################################################################################
 
-# note the location for later use (eg, in job scripts)
+#
+# These are the defaults for this version which should generally be
+# overridden from the prefs.sh file or from command-line specification
+#
+#- note the location for later use (eg, in job scripts)
 : ${FOAM_INST_DIR:=$foamInstall}; export FOAM_INST_DIR
 
+#- ParaView version, automatically determine major version:
+export ParaView_VERSION=3.8.0
+export ParaView_MAJOR=unknown
+
+#- Compiler location:
+#    foamCompiler= system | ThirdParty (OpenFOAM)
+foamCompiler=system
+
+#- Compiler:
+#    WM_COMPILER = Gcc | Gcc43 | Gcc44 | Gcc45 | Clang | Icc (Intel icc)
+export WM_COMPILER=Gcc
+unset WM_COMPILER_ARCH WM_COMPILER_LIB_ARCH
+
+#- Architecture:
+#    WM_ARCH_OPTION = 32 | 64
+export WM_ARCH_OPTION=64
+
+#- Precision:
+#    WM_PRECISION_OPTION = DP | SP
+export WM_PRECISION_OPTION=DP
+
+#- Optimised, debug, profiling:
+#    WM_COMPILE_OPTION = Opt | Debug | Prof
+export WM_COMPILE_OPTION=Opt
+
+#- MPI implementation:
+#    WM_MPLIB = SYSTEMOPENMPI | OPENMPI | MPICH | MPICH-GM | HPMPI
+#               | GAMMA | MPI | QSMPI
+export WM_MPLIB=OPENMPI
+
+#- Operating System:
+#    WM_OSTYPE = POSIX | ???
+export WM_OSTYPE=POSIX
+
+#- Floating-point signal handling:
+#    set or unset
+export FOAM_SIGFPE=
+
+#- memory initialisation:
+#    set or unset
+#export FOAM_SETNAN=
+
+
+################################################################################
+
 # The old dirs to be cleaned from the various environment variables
 # - remove anything under top-level directory.
 # NB: the WM_PROJECT_INST_DIR might not be identical between versions
@@ -90,6 +139,7 @@ _foamSource()
 _foamSource `$WM_PROJECT_DIR/bin/foamEtcFile prefs.sh`
 
 # Evaluate command-line parameters and record settings for later
+# these can be used to set/unset values, or specify prefs files
 export FOAM_SETTINGS="$@"
 while [ $# -gt 0 ]
 do
@@ -116,41 +166,6 @@ do
 done
 
 
-# Operating System/Platform
-# ~~~~~~~~~~~~~~~~~~~~~~~~~
-# WM_OSTYPE = POSIX | ????
-: ${WM_OSTYPE:=POSIX}; export WM_OSTYPE
-
-
-# Compiler: set to Gcc, Gcc43, Gcc44, or Icc (for Intel's icc)
-# ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-: ${WM_COMPILER:=Gcc}; export WM_COMPILER
-
-unset WM_COMPILER_ARCH WM_COMPILER_LIB_ARCH
-
-
-# Compilation options (architecture, precision, optimised, debug or profiling)
-# ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-# WM_ARCH_OPTION = 32 | 64
-: ${WM_ARCH_OPTION:=64}; export WM_ARCH_OPTION
-
-# WM_PRECISION_OPTION = DP | SP
-: ${WM_PRECISION_OPTION:=DP}; export WM_PRECISION_OPTION
-
-# WM_COMPILE_OPTION = Opt | Debug | Prof
-: ${WM_COMPILE_OPTION:=Opt}; export WM_COMPILE_OPTION
-
-# WM_MPLIB = SYSTEMOPENMPI | OPENMPI | MPICH | MPICH-GM | HPMPI | GAMMA
-#                          | MPI | QSMPI
-: ${WM_MPLIB:=OPENMPI}; export WM_MPLIB
-
-
-# Run options (floating-point signal handling and memory initialisation)
-# ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-export FOAM_SIGFPE=
-# export FOAM_SETNAN=
-
-
 # Detect system type and set environment variables appropriately
 # ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 export WM_ARCH=`uname -s`
@@ -165,7 +180,7 @@ Linux)
         ;;
 
     x86_64)
-        case $WM_ARCH_OPTION in
+        case "$WM_ARCH_OPTION" in
         32)
             export WM_COMPILER_ARCH='-64'
             export WM_CC='gcc'
@@ -196,13 +211,13 @@ Linux)
 
     mips64)
         WM_ARCH=SiCortex64
+        WM_MPLIB=MPI
         export WM_COMPILER_LIB_ARCH=64
         export WM_CC='gcc'
         export WM_CXX='g++'
         export WM_CFLAGS='-mabi=64 -fPIC'
         export WM_CXXFLAGS='-mabi=64 -fPIC'
         export WM_LDFLAGS='-mabi=64 -G0'
-        export WM_MPLIB=MPI
         ;;
 
     ppc64)
@@ -223,13 +238,13 @@ Linux)
 
 SunOS)
     WM_ARCH=SunOS64
+    WM_MPLIB=FJMPI
     export WM_COMPILER_LIB_ARCH=64
     export WM_CC='gcc'
     export WM_CXX='g++'
     export WM_CFLAGS='-mabi=64 -fPIC'
     export WM_CXXFLAGS='-mabi=64 -fPIC'
     export WM_LDFLAGS='-mabi=64 -G0'
-    export WM_MPLIB=FJMPI
     ;;
 
 *)    # an unsupported operating system
diff --git a/etc/cshrc b/etc/cshrc
index 0ef3f0ce78ce345c33d931f32ced7fe6c155a4d5..2a7369913779bc24c3a66e47dd79220b3e27f82c 100644
--- a/etc/cshrc
+++ b/etc/cshrc
@@ -34,24 +34,74 @@ setenv WM_PROJECT OpenFOAM
 setenv WM_PROJECT_VERSION dev
 
 ################################################################################
-# USER EDITABLE PART. Note changes made here may be lost with the next upgrade
+# USER EDITABLE PART: Changes made here may be lost with the next upgrade
 #
-#    either setenv FOAM_INST_DIR before sourcing this file or set
-#    foamInstall below to where OpenFOAM is installed
+# either setenv FOAM_INST_DIR before sourcing this file or set
+# 'foamInstall' below to where OpenFOAM is installed
 #
 # Location of the OpenFOAM installation
 # ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 set foamInstall = $HOME/$WM_PROJECT
 # set foamInstall = ~$WM_PROJECT
-# set foamInstall = /usr/local/$WM_PROJECT
 # set foamInstall = /opt/$WM_PROJECT
+# set foamInstall = /usr/local/$WM_PROJECT
 #
 # END OF (NORMAL) USER EDITABLE PART
 ################################################################################
 
-# note the location for later use (eg, in job scripts)
+#
+# These are the defaults for this version which should generally be
+# overridden from the prefs.csh file or from command-line specification
+#
+#- note the location for later use (eg, in job scripts)
 if ( ! $?FOAM_INST_DIR ) setenv FOAM_INST_DIR $foamInstall
 
+#- ParaView version, automatically determine major version:
+setenv ParaView_VERSION 3.8.0
+setenv ParaView_MAJOR unknown
+
+#- Compiler location:
+#    foamCompiler= system | ThirdParty (OpenFOAM)
+set foamCompiler=system
+
+#- Compiler:
+#    WM_COMPILER = Gcc | Gcc43 | Gcc44 | Gcc45 | Clang | Icc (Intel icc)
+setenv WM_COMPILER Gcc
+setenv WM_COMPILER_ARCH # defined but empty
+setenv WM_COMPILER_LIB_ARCH # defined but empty
+#
+#- Architecture:
+#    WM_ARCH_OPTION = 32 | 64
+setenv WM_ARCH_OPTION 64
+
+#- Precision:
+#    WM_PRECISION_OPTION = DP | SP
+setenv WM_PRECISION_OPTION DP
+
+#- Optimised, debug, profiling:
+#    WM_COMPILE_OPTION = Opt | Debug | Prof
+setenv WM_COMPILE_OPTION Opt
+
+#- MPI implementation:
+#    WM_MPLIB = SYSTEMOPENMPI | OPENMPI | MPICH | MPICH-GM | HPMPI
+#               | GAMMA | MPI | QSMPI
+setenv WM_MPLIB OPENMPI
+
+#- Operating System:
+#    WM_OSTYPE = POSIX | ???
+setenv WM_OSTYPE POSIX
+
+#- Floating-point signal handling:
+#    set or unset
+setenv FOAM_SIGFPE
+
+#- memory initialisation:
+#    set or unset
+#setenv FOAM_SETNAN
+
+
+################################################################################
+
 # The old dirs to be cleaned from the various environment variables
 # - remove anything under top-level directory.
 # NB: the WM_PROJECT_INST_DIR might not be identical between versions
@@ -75,6 +125,7 @@ alias _foamSource 'if ($?FOAM_VERBOSE && $?prompt) echo "Sourcing: \!*"; if (\!*
 _foamSource `$WM_PROJECT_DIR/bin/foamEtcFile prefs.csh`
 
 # Evaluate command-line parameters and record settings for later
+# these can be used to set/unset values, or specify prefs files
 setenv FOAM_SETTINGS "${*}"
 while ( $#argv > 0 )
     switch ($argv[1])
@@ -99,41 +150,6 @@ while ( $#argv > 0 )
 end
 
 
-# Operating System/Platform
-# ~~~~~~~~~~~~~~~~~~~~~~~~~
-# WM_OSTYPE = POSIX | ????
-if ( ! $?WM_OSTYPE ) setenv WM_OSTYPE POSIX
-
-
-# Compiler: set to Gcc, Gcc43, Gcc44 or Icc (for Intel's icc)
-# ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-if ( ! $?WM_COMPILER ) setenv WM_COMPILER Gcc
-
-setenv WM_COMPILER_ARCH
-setenv WM_COMPILER_LIB_ARCH
-
-
-# Compilation options (architecture, precision, optimised, debug or profiling)
-# ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-# WM_ARCH_OPTION = 32 | 64
-if ( ! $?WM_ARCH_OPTION ) setenv WM_ARCH_OPTION 64
-
-# WM_PRECISION_OPTION = DP | SP
-if ( ! $?WM_PRECISION_OPTION ) setenv WM_PRECISION_OPTION DP
-
-# WM_COMPILE_OPTION = Opt | Debug | Prof
-if ( ! $?WM_COMPILE_OPTION ) setenv WM_COMPILE_OPTION Opt
-
-# WM_MPLIB = SYSTEMOPENMPI | OPENMPI | MPICH | MPICH-GM | HPMPI | GAMMA | MPI | QSMPI
-if ( ! $?WM_MPLIB ) setenv WM_MPLIB OPENMPI
-
-
-# Run options (floating-point signal handling and memory initialisation)
-# ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-setenv FOAM_SIGFPE
-# setenv FOAM_SETNAN
-
-
 # Detect system type and set environment variables
 # ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 setenv WM_ARCH `uname -s`
@@ -181,13 +197,13 @@ case Linux:
 
     case mips64:
         setenv WM_ARCH SiCortex64
+        setenv WM_MPLIB MPI
         setenv WM_COMPILER_LIB_ARCH 64
         setenv WM_CC 'gcc'
         setenv WM_CXX 'g++'
         setenv WM_CFLAGS '-mabi=64 -fPIC'
         setenv WM_CXXFLAGS '-mabi=64 -fPIC'
         setenv WM_LDFLAGS '-mabi=64 -G0'
-        setenv WM_MPLIB MPI
         breaksw
 
     case ppc64:
@@ -209,13 +225,13 @@ case Linux:
 
 case SunOS:
     setenv WM_ARCH SunOS64
+    setenv WM_MPLIB FJMPI
     setenv WM_COMPILER_LIB_ARCH 64
     setenv WM_CC 'gcc'
     setenv WM_CXX 'g++'
     setenv WM_CFLAGS '-mabi=64 -fPIC'
     setenv WM_CXXFLAGS '-mabi=64 -fPIC'
     setenv WM_LDFLAGS '-mabi=64 -G0'
-    setenv WM_MPLIB FJMPI
     breaksw
 
 default:
diff --git a/etc/settings.csh b/etc/settings.csh
index 6713fda203fadd88078b4129007e933ff025e9a5..36ede3f98a747752c94b087ebd1318cfdafd5e12 100644
--- a/etc/settings.csh
+++ b/etc/settings.csh
@@ -83,10 +83,14 @@ unset gcc_version gmp_version mpfr_version mpc_version
 unsetenv MPFR_ARCH_PATH
 
 
-# Select compiler installation
-# ~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-# foamCompiler = system | ThirdParty (OpenFOAM)
-if ( ! $?foamCompiler ) set foamCompiler=system
+# Location of compiler installation
+# ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+if ( ! $?foamCompiler ) then
+then
+    foamCompiler=system
+    echo "Warning in $WM_PROJECT_DIR/etc/settings.csh:"
+    echo "    foamCompiler not set, using '$foamCompiler'"
+fi
 
 switch ("$foamCompiler")
 case OpenFOAM:
@@ -146,7 +150,7 @@ case ThirdParty:
             echo "Warning in $WM_PROJECT_DIR/etc/settings.csh:"
             echo "    Cannot find $gccDir installation."
             echo "    Please install this compiler version or if you wish to use the system compiler,"
-            echo "    change the 'foamCompiler' setting to 'system' in this file"
+            echo "    change the 'foamCompiler' setting to 'system'"
             echo
         endif
 
@@ -184,7 +188,7 @@ case ThirdParty:
             echo "Warning in $WM_PROJECT_DIR/etc/settings.csh:"
             echo "    Cannot find $clangDir installation."
             echo "    Please install this compiler version or if you wish to use the system compiler,"
-            echo "    change the 'foamCompiler' setting to 'system' in this file"
+            echo "    change the 'foamCompiler' setting to 'system'"
             echo
         endif
 
@@ -194,6 +198,15 @@ case ThirdParty:
     unset clang_version clangDir
 
     breaksw
+
+case system:
+    # okay, use system compiler
+    breaksw
+
+default:
+    echo "Warn: foamCompiler='$foamCompiler' is unsupported"
+    echo "   treating as 'system' instead"
+    breaksw
 endsw
 
 
diff --git a/etc/settings.sh b/etc/settings.sh
index 4a55023568bd30d00523434cb05987da03d5783d..7f1083e0b870ab14c3b68d84dcded4dbbcd5c49d 100644
--- a/etc/settings.sh
+++ b/etc/settings.sh
@@ -105,10 +105,14 @@ _foamAddLib  $FOAM_USER_LIBBIN:$FOAM_SITE_LIBBIN:$FOAM_LIBBIN:$FOAM_LIBBIN/dummy
 unset gcc_version gmp_version mpfr_version mpc_version
 unset MPFR_ARCH_PATH
 
-# Select compiler installation
-# ~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-# foamCompiler = system | ThirdParty (OpenFOAM)
-: ${foamCompiler:=system}
+# Location of compiler installation
+# ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+if [ -z "$foamCompiler" ]
+then
+    foamCompiler=system
+    echo "Warning in $WM_PROJECT_DIR/etc/settings.sh:" 1>&2
+    echo "    foamCompiler not set, using '$foamCompiler'" 1>&2
+fi
 
 case "${foamCompiler}" in
 OpenFOAM | ThirdParty)
@@ -163,7 +167,7 @@ OpenFOAM | ThirdParty)
             echo "Warning in $WM_PROJECT_DIR/etc/settings.sh:"
             echo "    Cannot find $gccDir installation."
             echo "    Please install this compiler version or if you wish to use the system compiler,"
-            echo "    change the 'foamCompiler' setting to 'system' in this file"
+            echo "    change the 'foamCompiler' setting to 'system'"
             echo
         }
 
@@ -204,7 +208,7 @@ OpenFOAM | ThirdParty)
             echo "Warning in $WM_PROJECT_DIR/etc/settings.sh:"
             echo "    Cannot find $clangDir installation."
             echo "    Please install this compiler version or if you wish to use the system compiler,"
-            echo "    change the 'foamCompiler' setting to 'system' in this file"
+            echo "    change the 'foamCompiler' setting to 'system'"
             echo
         }
 
@@ -213,6 +217,13 @@ OpenFOAM | ThirdParty)
     fi
     unset clang_version clangDir
     ;;
+system)
+    # okay, use system compiler
+    ;;
+*)
+    echo "Warn: foamCompiler='$foamCompiler' is unsupported" 1>&2
+    echo "   treating as 'system' instead" 1>&2
+    ;;
 esac