--- a/acinclude.m4	2020-05-02 04:51:52.819144394 +0200
+++ a/acinclude.m4	2020-05-11 01:03:45.989448120 +0200
@@ -406,7 +406,7 @@ 
     JAVAH=no
   ])
   AC_MSG_RESULT(${JAVAH})
-  if test "x${JAVAH}" == "xno"; then
+  if test "x${JAVAH}" = "xno"; then
     JAVAH=${JAVAH_DEFAULT}
   fi
   AC_MSG_CHECKING([if $JAVAH is a valid executable file])
@@ -443,7 +443,7 @@ 
     JAR=no
   ])
   AC_MSG_RESULT(${JAR})
-  if test "x${JAR}" == "xno"; then
+  if test "x${JAR}" = "xno"; then
     JAR=${JAR_DEFAULT}
   fi
   AC_MSG_CHECKING([if $JAR is a valid executable file])
@@ -1995,7 +1995,7 @@ 
   [ 
     PAX_COMMAND=${pax_active}
   ])
-  if test "x${PAX_COMMAND}" == "xyes"; then
+  if test "x${PAX_COMMAND}" = "xyes"; then
     AC_MSG_RESULT([no])
     PAX_COMMAND=${PAX_DEFAULT}
     AC_MSG_NOTICE([PaX enabled but no tool specified; using ${PAX_DEFAULT}])
@@ -2720,7 +2720,7 @@ 
   REAL_GCC=$(${READLINK} -e ${ABS_CC})
   if test "x$(basename ${REAL_GCC})" = "xccache"; then
      AC_MSG_RESULT([yes; ${CC} resolves to ${REAL_GCC}])
-     NO_CCACHE_PATH=$(sed "s#@<:@^:@:>@*$(dirname ${ABS_CC}):##g" <<< "${PATH}")
+     NO_CCACHE_PATH=$(printf %s "${PATH}" | sed "s#@<:@^:@:>@*$(dirname ${ABS_CC}):##g")
      AC_MSG_NOTICE([Using ${NO_CCACHE_PATH} as PATH])
   else
      AC_MSG_RESULT([no; ${CC} resolves to ${REAL_GCC}])