Flaky CI test issue after #154

[Kyle-Ye]

I can randomly reproduce it locally by OPENGRAPH_COMPATIBILITY_TEST=1 swift test.

System Integrity Protection: enabled

Crashed Thread:        5

Exception Type:        EXC_BAD_ACCESS (SIGSEGV)
Exception Codes:       KERN_INVALID_ADDRESS at 0x00006b3e96f90060
Exception Codes:       0x0000000000000001, 0x00006b3e96f90060

Termination Reason:    Namespace SIGNAL, Code 11 Segmentation fault: 11
Terminating Process:   exc handler [44998]

VM Region Info: 0x6b3e96f90060 is not in any region.  
      REGION TYPE                    START - END         [ VSIZE] PRT/MAX SHRMOD  REGION DETAIL
      UNUSED SPACE AT START
--->  
      UNUSED SPACE AT END

Thread 0::  Dispatch queue: com.apple.main-thread
0   Foundation                    	       0x18d6db184 specialized BidirectionalCollection._range<A>(of:anchored:backwards:) + 1020
1   Foundation                    	       0x18d6e6994 specialized _StringCompareOptionsIterable._range<A>(of:toHalfWidth:diacriticsInsensitive:caseFold:anchored:backwards:) + 316
2   Foundation                    	       0x18dcb3474 StringProtocol.contains<A>(_:) + 392
3   Testing                       	       0x100a4c7d4 SourceLocation.init(fileID:filePath:line:column:) + 132
4   OpenGraphPackageTests         	       0x100e90370 freestanding macro expansion #1 of require in module OpenGraphCxxTests file DebugServerTests.swift line 28 column 23 + 332 (@__swiftmacro_17OpenGraphCxxTests0027DebugServerTestsswift_ovFAhfMX27_22_7requirefMf_.swift:3) [inlined]
5   OpenGraphPackageTests         	       0x100e90370 DebugServerTests.commandTest() + 508 (DebugServerTests.swift:28)

...
Thread 5 Crashed:
0   AttributeGraph                	       0x1bd89109c AG::Graph::Context::~Context() + 172
1   CoreFoundation                	       0x18c029bb4 _CFRelease + 296
2   OpenGraphPackageTests         	       0x100e0d0f4 AttributeTestBase.deinit + 52 (AttributeTestBase.swift:23)
3   OpenGraphPackageTests         	       0x100df759c AnyAttributeCompatibilityTests.deinit + 28