[SR-13424] Packages using .systemLibrary(name:pkgConfig:) can lead to a seg fault from Swift Package Manager

[swift-ci]

Previous ID	SR-13424
Radar	rdar://problem/67500702
Original Reporter	Dadoum (JIRA User)
Type	Bug

Attachment: Download

Environment

Observed in Manjaro Linux, 20.0 and 20.1, with the swift-bin AUR package. (CentOS toolchain with library name patches)

Additional Detail from JIRA

Votes	1
Component/s	Package Manager
Labels	Bug
Assignee	None
Priority	Medium

md5: d6c64958297b6bc1804042e9d37c4f1f

Issue Description:

On Arch-Linux-based distributions, using a system library with a pkgConfig arg will make SPM segfault. This is due to the use of realpath here

Edit: added lldb debugger trace

[typesanitizer]

@swift-ci create

[swift-ci]

Comment by Mikoláš Stuchlík (JIRA)

This issue was discussed by the SwiftGtk developers in rhx/SwiftGtk#43 .

I have built SPM from main using -serialize-debugging-options frontend option and run build command in lldb. The result is in file trace.txt

The issue is caused by circular dependencies in .pc files on Arch which results in looping the PkgConfig initializer.

Example of such behavior can be observed, when attempting to add package `pangocairo` using pkgConfig.