try to fix file_exists?

src/resolvers/git.cr

@@ -226,27 +226,19 @@ module Shards
       @local_path ||= begin
         uri = parse_uri(git_url)
 
-        Log.debug { "constructing path for #{git_url} - uri: #{uri} - uri.path: #{uri.path} - uri.host #{uri.host}" }
-
         path = uri.path
         path += ".git" unless path.ends_with?(".git")
-        Log.debug { "constructing path part 1: #{path}" }
 
         path = Path[path]
-        Log.debug { "constructing path part 2: #{path} - type: #{path.class}" }
 
         # E.g. turns "c:\local\path.git" into "c\local\path.git". Or just drops the leading slash.
         if (anchor = path.anchor)
           path = Path[path.drive.to_s.rchop(":"), path.relative_to(anchor)]
         end
 
-        Log.debug { "constructing path part 3: #{path} - type: #{path.class}" }
-
         if host = uri.host
-          Log.debug { "constructing path part 4.1: using host #{host}" }
           File.join(Shards.cache_path, host, path)
         else
-          Log.debug { "constructing path part 4.2: using path #{path}" }
           File.join(Shards.cache_path, path)
         end
       end
@@ -429,7 +421,7 @@ module Shards
     end
 
     private def file_exists?(ref : GitRef, path)
-      files = capture("git ls-tree -r --full-tree --name-only #{Process.quote(ref.to_git_ref)} -- #{Process.quote(path)}")
+      files = capture("git -C #{local_path} ls-tree -r --full-tree --name-only #{Process.quote(ref.to_git_ref)} -- #{Process.quote(path)}")
       !files.strip.empty?
     end