Improve the error message about missing PLY Python package

Previously, only a message about missing Python was printed, which was
misleading to many users.  The new message clearly states that Python
AND PLY is required and prints basic instructions how to install PLY
package.

diff --git a/configure b/configure
index 29bc6787d732463a5f120f35ee65f141e9f65757..1c56cf5a5f9d94af341e207434bddf96c50553a1 100755 (executable)
--- a/configure
+++ b/configure
@@ -12586,7 +12586,7 @@ fi
 $as_echo_n "checking for Python support... " >&6; }
              { $as_echo "$as_me:${as_lineno-$LINENO}: result: no" >&5
 $as_echo "no" >&6; }
-             as_fn_error $? "Python required for dnssec-keymgr" "$LINENO" 5
+             as_fn_error $? "Python >= 2.7 or >= 3.2 and the PLY package are required for dnssec-keymgr and other Python-based tools. PLY may be available from your OS package manager as python-ply or python3-ply; it can also be installed via pip. To build without Python/PLY, use --disable-python." "$LINENO" 5
 fi
 fi
 

diff --git a/configure.ac b/configure.ac
index 837768d84437fb869dcb1d83a4c6d479e9b6bd04..71a05e2eb13c72d4eeef152ac3ee9dbe9d3f0bdf 100644 (file)
--- a/configure.ac
+++ b/configure.ac
@@ -262,7 +262,15 @@ AS_IF([test "$with_python" = "no"],
        AS_IF([test "X$PYTHON" = "X"],
             [AC_MSG_CHECKING([for Python support])
              AC_MSG_RESULT([no])
-             AC_MSG_ERROR([Python required for dnssec-keymgr])])])
+             AC_MSG_ERROR([m4_normalize(
+                               [Python >= 2.7 or >= 3.2 and the PLY package
+                                 are required for dnssec-keymgr and other
+                                 Python-based tools. PLY may be
+                                 available from your OS package manager
+                                 as python-ply or python3-ply; it can also
+                                 be installed via pip. To build without
+                                 Python/PLY, use --disable-python.]
+                           )])])])
 
 PYTHON_TOOLS=''
 CHECKDS=''