id	summary	reporter	owner	description	type	status	priority	milestone	component	resolution	keywords	cc
811	Unhelpful error message when unable to write file	Philip		"When the game is unable to write a file (in particular when it's trying to create a cache file when it doesn't have write permission to the directory), it gives an error like
{{{
io.h(73): Assertion failed: ""fd >= 0""
Assertion failed: ""fd >= 0""
Location: io.h:73 (Validate)

...

errno = 0 (?)
OS error = ?
}}}
(via `io::Store` -> `io::Run` -> `io::Operation::Validate`) which is very uninformative. In contrast, if `CreateDirectories` fails due to permission problems, it says ""Function call failed: return value was -110300 (Insufficient access rights to open file)"" - it should do something similar when failing to create files."	task	closed	Should Have	Alpha 5	Core engine	fixed		jan