[SR-6422] Encountering "Constant strings cannot be deallocated" in Linux foundation

[mbrandonw]

Previous ID	SR-6422
Radar	None
Original Reporter	@mbrandonw
Type	Bug
Status	Resolved
Resolution	Duplicate

Additional Detail from JIRA

Votes	0
Component/s	Foundation
Labels	Bug, RunTimeCrash
Assignee	None
Priority	Medium

md5: 591e29ee8530d7b357e7037d4dee4824

duplicates:

• SR-6398 Constant strings cannot be deallocated: file Foundation/NSCFString.swift, line 118

Issue Description:

Hello! I have a test case that when run on Linux somehow encounters the "Constant strings cannot be deallocated” fatal error thrown in NSCFString.swift, as seen here:

https://github.com/apple/swift-corelibs-foundation/blob/master/Foundation/NSCFString.swift#L118

The test that does it is here:

https://github.com/pointfreeco/swift-web/blob/5f19a0264be5d369ee0438da8599e3c478a6573b/Tests/ApplicativeRouterTests/SyntaxRouterTests.swift#L88-L93

Now there’s a lot to unravel here and I haven’t been able to find a minimal test case yet, but I thought I would at least file this for now and can update if I find the minimal test case.

I have also raised this issue not he corelibs-dev mailing list:

https://lists.swift.org/pipermail/swift-corelibs-dev/Week-of-Mon-20171113/001351.html

Thanks!

[mbrandonw]

Hello! After some investigation we were able to find that most of these crashes have something to do with `URLQueryItem`s. In fact, it seems that it has to do with duplicate keys in a query string, as demonstrated here:

pointfreeco/swift-web@cfa9b51

You can see the failure on this Travis CI output:

https://travis-ci.org/pointfreeco/swift-web/builds/309316418?utm_source=email&utm_medium=notification

At the bottom we have:
fatal error: Constant strings cannot be deallocated: file Foundation/NSCFString.swift, line 118

[parkera]

I think we've tracked this down. We'll fix with SR-6398.