do not validate variants of concrete specs in solver setup (#22272)

Currently, regardless of a spec being concrete or not, we validate its variants in `spec_clauses` (part of `SpackSolverSetup`).  

This PR skips the check if the spec is concrete.

The reason we want to do this is so that the solver setup class (really, `spec_clauses`) can be used for cases when we just want the logic statements / facts (is that what they are called?) and we don't need to re-validate an already concrete spec.  We can't change existing concrete specs, and we have to be able to handle them *even if they violate constraints in the current spack*.  This happens in practice if we are doing the validation for a spec produced by a different spack install.

Signed-off-by: vsoch <vsoch@users.noreply.github.com>

1 files changed, 11 insertions, 10 deletions

diff --git a/lib/spack/spack/solver/asp.py b/lib/spack/spack/solver/asp.py
index 975dbfcc91..01536f267f 100644
--- a/lib/spack/spack/solver/asp.py
+++ b/lib/spack/spack/solver/asp.py
@@ -966,16 +966,17 @@ class SpackSolverSetup(object):
                 if value == '*':
                     continue
 
-                # validate variant value
-                reserved_names = spack.directives.reserved_names
-                if not spec.virtual and vname not in reserved_names:
-                    try:
-                        variant_def = spec.package.variants[vname]
-                    except KeyError:
-                        msg = 'variant "{0}" not found in package "{1}"'
-                        raise RuntimeError(msg.format(vname, spec.name))
-                    else:
-                        variant_def.validate_or_raise(variant, spec.package)
+                # validate variant value only if spec not concrete
+                if not spec.concrete:
+                    reserved_names = spack.directives.reserved_names
+                    if not spec.virtual and vname not in reserved_names:
+                        try:
+                            variant_def = spec.package.variants[vname]
+                        except KeyError:
+                            msg = 'variant "{0}" not found in package "{1}"'
+                            raise RuntimeError(msg.format(vname, spec.name))
+                        else:
+                            variant_def.validate_or_raise(variant, spec.package)
 
                 clauses.append(f.variant_value(spec.name, vname, value))