dealing with undefined option variables.

Author: LutzGross

SConstruct

@@ -249,9 +249,16 @@ if env['tools_names'] != ['default']:
 Help(vars.GenerateHelpText(env))
 # Check for superfluous options
 if len(vars.UnknownVariables())>0:
+    APPROVED_VARIABLES = [ 'os', 'subprocess']
+    DEL= ""
     for k in vars.UnknownVariables():
-        print("Unknown option '%s'" % k)
-    Exit(1)
+        if not k in APPROVED_VARIABLES:
+            print("Unknown option variable '%s'" % k)
+            DEL+=k+", "
+    if len(DEL)>0:
+        print("Most likely these variables are set in the options file. Add the following statement to delete them:")
+        print("\n  del "+DEL[:-2]+"\n")
+        Exit(1)
 
 env['domains'] = sorted(set(env['domains']))
 #===== First thing we do is to install Trilinos if requested to do so:

scons/templates/README_FIRST

@@ -20,6 +20,10 @@ If you can't find a matching template file you can either import one that
 comes close or start from scratch and set the options as required. All
 recognised options are explained below.
 
+Delete all variables that are not option variables. In some cases, variables
+that are introduced in option files and that are not option variables can trigger
+an error in scons.
+
 Prefixes
 ========
 

scons/templates/homebrew_options.py

@@ -30,6 +30,7 @@
 escript_opts_version = 203
 
 HOMEBREW_PREFIX = '/opt/homebrew'
+
 pythoncmd = os.path.join(HOMEBREW_PREFIX, 'bin', 'python3')
 import subprocess
 p=subprocess.run([pythoncmd, '-V'], capture_output=True, text=True)
@@ -113,3 +114,5 @@
 ld_extra = ["-L/opt/homebrew/opt/llvm/lib", "-lz", "-Wl,-rpath,/opt/homebrew/opt/llvm/lib/c++" ]
 
 
+# clean up:
+del HOMEBREW_PREFIX, p, subversion, revversion, t