When iterating, make all iteropts except builddependencies lists

Since some easyblocks, e.g. `CMakeMake` modify `self.cfg['configopts']`
it's safer to start afresh for every iteration. This PR implements
this by turning options like these, if not already lists,
into lists with identical element copies, e.g.
`[self.cfg['configopts']] * <number_of_iterations>`

This modification does not affect the logic of iterative `builddependencies`
itself since it is used in some other places in the code.

Author: bartoldeman

easybuild/framework/easyblock.py

@@ -2380,8 +2380,13 @@ def handle_iterate_opts(self):
             # only needs to be done during first iteration, since after that the options won't be lists anymore
             if self.iter_idx == 0:
                 # keep track of list, supply first element as first option to handle
+                iter_cnt = self.det_iter_cnt()
                 for opt in self.cfg.iterate_options:
-                    self.iter_opts[opt] = self.cfg[opt]  # copy
+                    if isinstance(self.cfg[opt], (list, tuple)):
+                        self.iter_opts[opt] = self.cfg[opt]  # copy
+                    elif iter_cnt > 1:
+                        # make iter_cnt copies for every opt since easyblocks can modify them
+                        self.iter_opts[opt] = [self.cfg[opt]] * iter_cnt
                     self.log.debug("Found list for %s: %s", opt, self.iter_opts[opt])
 
             if self.iter_opts:

easybuild/framework/easyconfig/easyconfig.py

@@ -1037,14 +1037,8 @@ def validate_iterate_opts_lists(self):
     def start_iterating(self):
         """Start iterative mode."""
 
-        for opt in ITERATE_OPTIONS:
-            # builddpendencies is already handled, see __init__
-            if opt == 'builddependencies':
-                continue
-
-            # list of values indicates that this is a value to iterate over
-            if isinstance(self[opt], (list, tuple)):
-                self.iterate_options.append(opt)
+        # builddependencies is already handled, see __init__
+        self.iterate_options.extend([opt for opt in ITERATE_OPTIONS if opt != 'builddependencies'])
 
         # keep track of when we're iterating (used by builddependencies())
         self.iterating = True