RF: Going one step further and completely overwriting any -rpath settings

specified in environment. This is to support local development, so that
exes can be executed from $FSLDIR/src/<project>/<exe> and that libs in
$FSLDIR/src/<project>/ will take precedence over those in $FSLDIR/lib/

config/buildSettings.mk

@@ -10,6 +10,9 @@
 # get system type (Darwin, Linux)
 SYSTYPE := $(shell uname -s)
 
+# For string substitution
+COMMA   := ,
+
 #####################################################################
 #
 # Standard commands
@@ -77,6 +80,21 @@ ARCHNVCCLDFLAGS =
 # macOS.
 #
 #####################################################################
+
+# Drop -rpath flags from LDFLAGS if it is
+# set in the environment - we explicitly
+# add them below such that executables
+# will be able to find libs in $(pwd) and
+# in $FSLDIR/lib *in that order*. This is
+# so that executables located in the
+# project source dir can be executed in
+# place with sensible behaviour (i.e.  any
+# shared libs located in the same dir will
+# take precedence over libs of the same
+# name in $FSLDIR/lib/).
+_LDFLAGS := $(patsubst -Wl${COMMA}-rpath%,,${LDFLAGS})
+LDFLAGS   = ${_LDFLAGS}
+
 ifeq ($(SYSTYPE), Darwin)
 
   # CC, CXX, CFLAGS, CXXFLAGS, and LDFLAGS
@@ -85,14 +103,7 @@ ifeq ($(SYSTYPE), Darwin)
   CXX      ?= clang++
   CFLAGS   ?= -arch x86_64 -Wall -pedantic
   CXXFLAGS ?= -arch x86_64 -Wall -pedantic
-
-  # Set rpath so that executables will be
-  # able to find libs in $FSLDIR/lib, and
-  # in $(pwd) (for execution from project
-  # source dir).  Same below for linux.
-  LDFLAGS  ?=
-  LDFLAGS  += -Wl,-rpath,"@executable_path/"       \
-              -Wl,-rpath,"@executable_path/../lib" \
+  LDFLAGS  += -Wl,-rpath,"@executable_path/" \
               -Wl,-rpath,"${FSLDIR}/lib"
   ARCHLIBS += -llapack -lblas -lz -lm
 
@@ -121,10 +132,8 @@ ifeq ($(SYSTYPE), Linux)
               -Wall -pedantic -Wno-long-long
   CXXFLAGS ?= -fexpensive-optimizations \
               -Wall -pedantic -Wno-long-long
-  LDFLAGS  ?=
-  LDFLAGS  += -Wl,-rpath='$$ORIGIN'        \
-              -Wl,-rpath='$$ORIGIN/../lib' \
-              -Wl,-rpath="${FSLDIR}/lib"
+  LDFLAGS  += -Wl,-rpath,'$$ORIGIN:${FSLDIR}/lib' \
+              -Wl,-rpath-link,'$$ORIGIN:${FSLDIR}/lib'
   ARCHLIBS += -lopenblas -lz -lm
 endif