diff --git a/configure.in b/configure.in
index e7c2cf5fd757a47a22a5ee5514e41e9738f21db2..450866b81f1652a307aebe1c4455e3b3f6268f51 100644
--- a/configure.in
+++ b/configure.in
@@ -652,7 +652,7 @@ CPPFLAGS="$OLD_CPPFLAGS -m32"
 AC_PREPROC_IFELSE(
   [AC_LANG_SOURCE([/* Check if preprocessor supports option -m32 */])],
   [if test -e conftest.i; then
-    DEFAULT_CPP_SUPPORTED_ARCH_OPTS+='\"-m32\"; ';
+    DEFAULT_CPP_SUPPORTED_ARCH_OPTS="$DEFAULT_CPP_SUPPORTED_ARCH_OPTS "'\"-m32\";';
   fi], [])
 
 rm -f conftest.i
@@ -660,7 +660,7 @@ CPPFLAGS="$OLD_CPPFLAGS -m64"
 AC_PREPROC_IFELSE(
   [AC_LANG_SOURCE([/* Check if preprocessor supports option -m64 */])],
   [if test -e conftest.i; then
-    DEFAULT_CPP_SUPPORTED_ARCH_OPTS+='\"-m64\"; ';
+    DEFAULT_CPP_SUPPORTED_ARCH_OPTS="$DEFAULT_CPP_SUPPORTED_ARCH_OPTS "'\"-m64\";';
   fi], [])
 
 rm -f conftest.i
@@ -668,13 +668,13 @@ CPPFLAGS="$OLD_CPPFLAGS -m16"
 AC_PREPROC_IFELSE(
   [AC_LANG_SOURCE([/* Check if preprocessor supports option -m16 */])],
   [if test -e conftest.i; then
-    DEFAULT_CPP_SUPPORTED_ARCH_OPTS+='\"-m16\"; ';
+    DEFAULT_CPP_SUPPORTED_ARCH_OPTS="$DEFAULT_CPP_SUPPORTED_ARCH_OPTS "'\"-m16\";';
   fi], [])
 
 # revert CPPFLAGS to original value
 CPPFLAGS=$OLD_CPPFLAGS
 
-AC_MSG_RESULT(Default preprocessor supported architecture-related options: $DEFAULT_CPP_SUPPORTED_ARCH_OPTS)
+AC_MSG_RESULT(Default preprocessor supported architecture-related options:$DEFAULT_CPP_SUPPORTED_ARCH_OPTS)
 
 
 #################
diff --git a/share/analysis-scripts/analysis.mk b/share/analysis-scripts/analysis.mk
index 4984908d62fbdbc85e8cf6b38912c14f961ad84e..3483b89d6d4689e36703eebed525d4ff2f79223a 100644
--- a/share/analysis-scripts/analysis.mk
+++ b/share/analysis-scripts/analysis.mk
@@ -65,12 +65,15 @@ ifneq (4.0,$(firstword $(sort $(MAKE_VERSION) 4.0)))
   $(error This Makefile requires Make >= 4.0 - available at http://ftp.gnu.org/gnu/make/)
 endif
 
-# Test if on a Mac (and therefore sed has fewer options)
-# Also test if /usr/bin/time is available, otherwise use the shell builtin
+# Test if sed has the '--unbuffered' option (GNU sed has, but neither macOS'
+# nor Busybox' have it, in which case we ignore it)
+SED_UNBUFFERED:=sed$(shell sed --unbuffered //p /dev/null 2>/dev/null && echo " --unbuffered" || true)
+
+# Test if on a Mac;
+# test if /usr/bin/time is available, otherwise use the shell builtin
 # (which has less options)
 UNAME := $(shell uname -s)
 ifeq ($(UNAME),Darwin)
-  SED_UNBUFFERED:=sed
 ifneq (,$(wildcard /usr/bin/time))
 define time_with_output
   /usr/bin/time -p
@@ -81,7 +84,6 @@ define time_with_output
 endef
 endif
 else
-  SED_UNBUFFERED:=sed --unbuffered
 ifneq (,$(wildcard /usr/bin/time))
 define time_with_output
   /usr/bin/time -f 'user_time=%U\nmemory=%M' -o "$(1)"
diff --git a/tests/spec/preprocess_dos.sh b/tests/spec/preprocess_dos.sh
index a63a982d043b5847b333d4e556892393f97c8a7d..26b571be5e0e46e39d4e8b0e8e2cfed89a498586 100755
--- a/tests/spec/preprocess_dos.sh
+++ b/tests/spec/preprocess_dos.sh
@@ -1,3 +1,5 @@
 #!/bin/sh
 gcc -C -E -I. -o $3 $2
-$1 -q $3
+# Note: some versions of dos2unix (e.g. Busybox) do not have a '-q' flag,
+# so we avoid using them
+$1 $3 >/dev/null 2>/dev/null