improve file comparison on weird filesystems (#167)

Co-authored-by: Christopher Doris <github.com/cjdoris>

Author: cjdoris

src/resolve.jl

@@ -26,6 +26,33 @@ function _resolve_env_is_clean(conda_env, meta)
     false
 end
 
+function issamefile(file1, file2)
+    ok1 = ispath(file1)
+    ok2 = ispath(file2)
+    if !ok1 && !ok2
+        # both files don't exist, which is the same in a sense
+        return true
+    elseif ok1 && ok2
+        # both files exist, so check if they are the same
+        return samefile(file1, file2)
+    else
+        # if one exists and the other doesn't, they are not the same
+        return false
+    end
+end
+
+function issameloadpath(load_path1, load_path2)
+    if length(load_path1) != length(load_path2)
+        return false
+    end
+    for (p1, p2) in zip(load_path1, load_path2)
+        if !issamefile(p1, p2)
+            return false
+        end
+    end
+    return true
+end
+
 function _resolve_can_skip_1(conda_env, load_path, meta_file)
     if !isdir(conda_env)
         @debug "conda env does not exist" conda_env
@@ -44,11 +71,11 @@ function _resolve_can_skip_1(conda_env, load_path, meta_file)
         @debug "meta version has changed" meta.version VERSION
         return false
     end
-    if meta.load_path != load_path
+    if !issameloadpath(meta.load_path, load_path)
         @debug "load path has changed" meta.load_path load_path
         return false
     end
-    if meta.conda_env != conda_env
+    if !issamefile(meta.conda_env, conda_env)
         @debug "conda env has changed" meta.conda_env conda_env
         return false
     end