No report of failed load attempt of requirements expressed with advanced version specifiers

[xdelaruelle]

When a requirement in a modulefile is expressed with the advanced version specifiers syntax:

$ ml show mod/1.0
-------------------------------------------------------------------
/path/to/modulefiles/mod/1.0:

prereq          unknown@1.2,1.4
-------------------------------------------------------------------

Automated load attempt of such requirement is not correctly reported in case of failure:

$ ml --auto mod/1.0
Loading mod/1.0
  ERROR: Unable to locate a modulefile for 'unknown@1.2,1.4'
  ERROR: mod/1.0 cannot be loaded due to missing prereq.
    HINT: the following module must be loaded first: unknown@1.2,1.4

Error message should mention that the load of the requirement were attempted.

Issue only occurs when advanced_version_spec configuration is enabled. Expected error message is obtained otherwise:

$ ml --auto mod/1.0
Loading mod/1.0
  ERROR: Unable to locate a modulefile for 'unknown@1.2,1.4'
  ERROR: Load of requirement 'unknown@1.2,1.4' failed