Allow empty version string
The interface for ToolArchives says that `version_str` is optional,
but when you try to use it with the default value, the QtArchives
constructor raises a ValueError exception. This change substitutes
the dummy value used by the Cli.run_install_tool for version_str, when
version_str is empty.
@@ -321,7 +321,7 @@ class ToolArchives(QtArchives):
super(ToolArchives, self).__init__(
os_name=os_name,
target=target,
- version_str=version_str,
+ version_str=version_str or "0.0.1", # dummy value
arch=arch,
base=base,
timeout=timeout,
