vault debug on Windows results in panic

[davemay99]

Describe the bug
When running vault debug from a Windows command line, a panic occurs while bundling the files.

To Reproduce
Steps to reproduce the behavior:

1. Run vault debug -duration=5s from a Windows command prompt
2. See panic

Expected behavior
The debug bundle should be written to a tarball.

Environment:

• Vault Server Version: n/a
• Vault CLI Version: any
• Server Operating System/Architecture: run the CLI on Windows

Additional context

Click to expand example

PS C:\git\hashicorp\vault> vault.exe debug -duration=5s

Overwriting interval value "30s" to the duration value "5s"
Overwriting metrics interval value "10s" to the duration value "5s"
==> Starting debug capture...
         Vault Address: http://127.0.0.1:8200
        Client Version: 1.9.4
              Duration: 5s
              Interval: 5s
      Metrics Interval: 5s
               Targets: config, host, metrics, pprof, replication-status, server-status, log
                Output: vault-debug-2022-03-07T19-47-30Z.tar.gz

==> Capturing static information...
2022-03-07T19:47:30.673Z [INFO]  capturing configuration state

==> Capturing dynamic information...
2022-03-07T19:47:30.773Z [INFO]  capturing metrics: count=0
2022-03-07T19:47:30.775Z [INFO]  capturing pprof data: count=0
2022-03-07T19:47:30.775Z [INFO]  capturing replication status: count=0
2022-03-07T19:47:30.775Z [INFO]  capturing server status: count=0
2022-03-07T19:47:30.775Z [INFO]  capturing host information: count=0
2022-03-07T19:47:35.774Z [INFO]  capturing metrics: count=1
2022-03-07T19:47:35.776Z [INFO]  capturing host information: count=1
2022-03-07T19:47:35.776Z [INFO]  capturing replication status: count=1
2022-03-07T19:47:35.776Z [INFO]  capturing server status: count=1
2022-03-07T19:47:36.084Z [INFO]  capturing pprof data: count=1
Finished capturing information, bundling files...
panic: interface conversion: interface {} is nil, not map[string]interface {}

goroutine 1 [running]:
github.com/hashicorp/vault/command.(*DebugCommand).generateIndex.func1({0xc0006196d0, 0xc0006196d0}, {0x6573348, 0xc00021ad20}, {0x0, 0x0})
        /home/runner/work/vault/vault/command/debug.go:336 +0x6a5
path/filepath.walk({0xc0006196d0, 0x41}, {0x6573348, 0xc00021ad20}, 0xc000b6fb90)
        /opt/hostedtoolcache/go/1.17.7/x64/src/path/filepath/path.go:418 +0x125
path/filepath.walk({0xc0007b9980, 0x35}, {0x6573348, 0xc00021acb0}, 0xc000b6fb90)
        /opt/hostedtoolcache/go/1.17.7/x64/src/path/filepath/path.go:442 +0x28f
path/filepath.walk({0xc0004ee300, 0x20}, {0x6573348, 0xc00021ac40}, 0xc000b6fb90)
        /opt/hostedtoolcache/go/1.17.7/x64/src/path/filepath/path.go:442 +0x28f
path/filepath.Walk({0xc0004ee300, 0x20}, 0xc000b6fb90)
        /opt/hostedtoolcache/go/1.17.7/x64/src/path/filepath/path.go:505 +0x6c
github.com/hashicorp/vault/command.(*DebugCommand).generateIndex(0xc0008611d0)
        /home/runner/work/vault/vault/command/debug.go:303 +0xdb
github.com/hashicorp/vault/command.(*DebugCommand).Run(0xc0008611d0, {0xc000148020, 0x1, 0x2})
        /home/runner/work/vault/vault/command/debug.go:275 +0x6fb
github.com/mitchellh/cli.(*CLI).Run(0xc000bbf7c0)
        /home/runner/go/pkg/mod/github.com/mitchellh/[email protected]/cli.go:262 +0x5f8
github.com/hashicorp/vault/command.RunCustom({0xc000148010, 0x2, 0x3}, 0xc00008e000)
        /home/runner/work/vault/vault/command/main.go:180 +0xa17
github.com/hashicorp/vault/command.Run(...)
        /home/runner/work/vault/vault/command/main.go:88
main.main()
        /home/runner/work/vault/vault/main.go:10 +0x52