[SR-2881] found nil while unwrapping an Optional value

[swift-ci]

Previous ID	SR-2881
Radar	None
Original Reporter	igouy2 (JIRA User)
Type	Bug
Status	Closed
Resolution	Invalid

Attachment: Download

Environment

swift-3.0.1-PREVIEW-1-ubuntu16.04

$ uname -a
Linux x64 4.4.0-38-generic #57-Ubuntu SMP Tue Sep 6 15:42:33 UTC 2016 x86_64 x86_64 x86_64 GNU/Linux

2.4Ghz Intel® Q6600® with 4GB of RAM and 250GB SATA II disk drive

Additional Detail from JIRA

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

md5: 8ca299b4d40bc77ca14931d26f7642aa

Issue Description:

$ /usr/local/src/swift-3.0.1-PREVIEW-1-ubuntu16.04/usr/bin/swiftc seg.swift -o seg

$ ./seg 0 < knucleotide-input.txt

fatal error: unexpectedly found nil while unwrapping an Optional value
Current stack trace:
0 libswiftCore.so 0x00007fe860a322f0 swift_reportError + 117
1 libswiftCore.so 0x00007fe860a43740 _swift_stdlib_reportFatalError + 61
2 libswiftCore.so 0x00007fe8608531b3 <unavailable> + 0
3 libswiftCore.so 0x00007fe8609ae27d <unavailable> + 0
4 libswiftCore.so 0x00007fe8608531b3 <unavailable> + 0
5 libswiftCore.so 0x00007fe860972280 specialized _fatalErrorMessage(StaticString, StaticString, StaticString, UInt, flags : UInt32) -> Never + 96
6 seg 0x0000000000401b0e <unavailable> + 0
7 seg 0x00000000004018b9 <unavailable> + 0
8 libc.so.6 0x00007fe85f4de740 __libc_start_main + 240
9 seg 0x0000000000401619 <unavailable> + 0
Illegal instruction (core dumped)

[belkadan]

The string produced in the callback to withCString is only valid during that callback.