[rm nixpkgs] Add more info on errors for debuggability (#1292)

## Summary
* ~Skips packages with missing store versions, since they're needed for
the store path.~
* Adds debug line and context to error msg to aid in debugging.

A related question: My understanding is that nix store paths are of the
form `/nix/store/<hash>-<pkg>`, and _not_ of the form
`/nix/store/<hash>-<pkg>-<version>`. Meaning that some (most) package
names just add the version suffix as convention. So I'm a bit worried
about trying to parse the version from the name and then essentially
reconstructing that here. Would prefer to just pass the untouched pkg
name and use that. @gcurtis why do we parse out the version separately
(if that's what we're doing)?

Another thing is I noticed that as long as the hash we pass to `nix
store make-content-addressed` is correct, then the rest doesn't matter.
Example:
```
> nix store make-content-addressed /nix/store/glb4gpim82f0bmzcpayvklbfqc6qzvwj-this-does-not-matter --json
asked 'https://cache.nixos.org' for '/nix/store/glb4gpim82f0bmzcpayvklbfqc6qzvwj-this-does-not-matter' but got '/nix/store/glb4gpim82f0bmzcpayvklbfqc6qzvwj-jq-1.6-bin' # <-- the path we want.
```
We could potentially try to recover from errors by using the path in
that response. (Update: I think it's ok to just fail instead of trying
to parse the response and recovering).

## How was it tested?
Manually by returning fake data from the calls to the search service.

Author: ipince

internal/lock/resolve.go

@@ -10,6 +10,7 @@ import (
 	"github.com/pkg/errors"
 	"go.jetpack.io/devbox/internal/boxcli/featureflag"
 	"go.jetpack.io/devbox/internal/boxcli/usererr"
+	"go.jetpack.io/devbox/internal/debug"
 	"go.jetpack.io/devbox/internal/nix"
 	"go.jetpack.io/devbox/internal/searcher"
 	"golang.org/x/exp/maps"
@@ -91,6 +92,7 @@ func buildLockSystemInfos(pkg *searcher.PackageVersion) (map[string]*SystemInfo,
 
 		// guard against missing search data
 		if sysInfo.StoreHash == "" || sysInfo.StoreName == "" {
+			debug.Log("WARN: skipping %s in %s due to missing store name or hash", pkg.Name, sysName)
 			continue
 		}
 
@@ -99,7 +101,7 @@ func buildLockSystemInfos(pkg *searcher.PackageVersion) (map[string]*SystemInfo,
 		if sysName == userSystem {
 			caStorePath, err = nix.ContentAddressedStorePath(storePath)
 			if err != nil {
-				return nil, err
+				return nil, errors.WithMessagef(err, "failed to make content addressed path for %s", storePath)
 			}
 		}
 		sysInfos[sysName] = &SystemInfo{