prepare Hydrilla package module for use from a containing git repo

1 files changed, 19 insertions, 11 deletions

diff --git a/guix-module-dir/hydrilla.scm b/guix-module-dir/hydrilla.scm
index 1e266af..6e74a0b 100644
--- a/guix-module-dir/hydrilla.scm
+++ b/guix-module-dir/hydrilla.scm
@@ -10,21 +10,29 @@
  (ice-9 rdelim)
  (ice-9 regex))
 
-;; We're mostly running from Makefile, so it's pretty safe to use `getcwd`.
-(define %source-dir (getcwd))
+(define %source-dir
+  (let* ((this-file (search-path %load-path "hydrilla.scm"))
+         (proj-dir (dirname (dirname this-file))))
+    (if (absolute-file-name? proj-dir)
+        proj-dir
+        (string-append (getcwd) "/" proj-dir))))
 
 ;; The PKG-INFO file is generated when running `python3 -m build -s` or similar.
 ;; It is also automatically included in the source release tarballs.
+(define %pkg-info-path
+  (string-append %source-dir "/src/hydrilla.egg-info/PKG-INFO"))
+
 (define %hydrilla-version
-  (if (access? "src/hydrilla.egg-info/PKG-INFO" R_OK)
-      (let* ((port (open-input-file "src/hydrilla.egg-info/PKG-INFO"))
-             (process-line
-              (lambda (self-ref)
-                (let ((match-result
-                       (string-match "^Version: (.*)" (read-line port))))
-                  (if match-result (match:substring match-result 1)
-                      (self-ref self-ref))))))
-        (process-line process-line))
+  (if (access? %pkg-info-path R_OK)
+      (call-with-input-file %pkg-info-path
+        (lambda (port)
+          (let ((process-line
+                 (lambda (self-ref)
+                   (let ((match-result
+                          (string-match "^Version: (.*)" (read-line port))))
+                     (if match-result (match:substring match-result 1)
+                         (self-ref self-ref))))))
+            (process-line process-line))))
       "unknown"))
 
 (define source-tarball-name