Panic in alpm cataloger

[cjnosal]

What happened:

panic: runtime error: index out of range [0] with length 0

goroutine 52 [running]:
github.com/anchore/syft/syft/pkg/cataloger/alpm.getFileReader({0xc0015cc270, 0xc2}, {0x64e35d8, 0xc0008b6000})
	/go/pkg/mod/github.com/anchore/syft@v0.55.0/syft/pkg/cataloger/alpm/parse_alpm_db.go:71 +0x1a5
github.com/anchore/syft/syft/pkg/cataloger/alpm.parseAlpmDB({0x64e35d8, 0xc0008b6000}, {0xc0007ee8f0, 0xc1}, {0x10e206d0, 0xc000a1e000})
	/go/pkg/mod/github.com/anchore/syft@v0.55.0/syft/pkg/cataloger/alpm/parse_alpm_db.go:217 +0xe7
github.com/anchore/syft/syft/pkg/cataloger/alpm.(*Cataloger).Catalog(0x60cf5fa?, {0x64e35d8, 0xc0008b6000})
	/go/pkg/mod/github.com/anchore/syft@v0.55.0/syft/pkg/cataloger/alpm/cataloger.go:45 +0x258
github.com/anchore/syft/syft/pkg/cataloger.Catalog({0x64e35d8?, 0xc0008b6000}, 0x8?, {0xc0008e2200, 0x14, 0x0?})
	/go/pkg/mod/github.com/anchore/syft@v0.55.0/syft/pkg/cataloger/catalog.go:55 +0x3ec
github.com/anchore/syft/syft.CatalogPackages(0xc001204580, {{0x1, 0x0, {0x60b896f, 0x8}}, {0x0, 0x0, 0x0}, 0x0})
	/go/pkg/mod/github.com/anchore/syft@v0.55.0/syft/lib.go:72 +0x5a5
github.com/anchore/syft/cmd/syft/cli/eventloop.generateCatalogPackagesTask.func1(0xc000602d00, 0xc001204580?)
	/go/pkg/mod/github.com/anchore/syft@v0.55.0/cmd/syft/cli/eventloop/tasks.go:49 +0xff
github.com/anchore/syft/cmd/syft/cli/eventloop.RunTask(0x46bac05?, 0xc0007ae3c0?, 0xc00052b7d0?, 0xc0006b82a0, 0xc000369560?)
	/go/pkg/mod/github.com/anchore/syft@v0.55.0/cmd/syft/cli/eventloop/tasks.go:223 +0x85
created by github.com/anchore/syft/cmd/syft/cli/packages.buildRelationships
	/go/pkg/mod/github.com/anchore/syft@v0.55.0/cmd/syft/cli/packages/packages.go:130 +0x65

What you expected to happen:
Either a successful inventory of alpm components or a graceful failure with informative message

How to reproduce it (as minimally and precisely as possible):

go install github.com/anchore/syft/cmd/syft@v0.55.0
git clone github.com/anchore/syft
syft -q dir:syft -o cyclonedx

Anything else we need to know?:
https://github.com/anchore/syft/blob/main/syft/pkg/cataloger/alpm/parse_alpm_db.go#L70
Couldn't reproduce on linux/amd64 go1.19 or darwin/amd64 go1.18.3

Environment:

• Output of syft version:
  Application: syft
  Version: [not provided]
  JsonSchemaVersion: 3.3.2
  BuildDate: [not provided]
  GitCommit: [not provided]
  GitDescription: [not provided]
  Platform: darwin/amd64
  GoVersion: go1.19
  Compiler: gc

[tgerla]

Hi @xtreme-conor-nosal, thank you for this report. We will take a look and get back to you if we need any more info.

[spiffcs]

@xtreme-conor-nosal I ran this with the latest code v0.63.0. We had some bug fixes and I ran you're reproducible steps and no panic was caused:

Closing this now as resolved - If you see anything wrong with the above output or you're not getting the correct result please let me know and I can re open