Support egg description file format for C5 added by mario-goulart on Tue Sep 4 14:26:57 2018

diff --git a/henrietta-cache.scm b/henrietta-cache.scm
index ba99aa2..832dcc3 100644
--- a/henrietta-cache.scm
+++ b/henrietta-cache.scm
@@ -174,15 +174,19 @@ EOF
           ((zip) (sprintf "unzip -d ~A -o -qq ~A" (qs dir) (qs archive)))
           (else (error (sprintf "Unknown archive type `~S' (shouldn't happen!)"
-    ((meta-file)
+    ((meta-file egg-file)
          (let* ((meta (car (call-with-input-request uri #f read-file)))
-                (files (alist-ref 'files meta)))
+                (files (or (alist-ref 'files meta)
+                           ;; Egg description files for C5 use
+                           ;; `distribution-files' to specify files to
+                           ;; cache.
+                           (alist-ref 'distribution-files meta))))
            (unless files
-             (error "No \"files\" entry found in meta file" uri))
+             (error "No \"files\" entry found in meta or egg file" uri))
            (download-files-from-list (uri-reference uri) files cache-dir))
        (e (exn http)
-          (error (sprintf "Could not download meta-file \"~A\" -- ~A\n"
+          (error (sprintf "Could not download meta or egg file \"~A\" -- ~A\n"
                           uri (get-condition-property e 'exn 'message))))))