Allow a placeholder ($DIR) to be used in utility paths to make it easier to use relative paths.

web/config.py

@@ -270,8 +270,13 @@ STORAGE_DIR = os.path.join(
 # expected to be overridden by packagers in config_distro.py.
 #
 # A default location can be specified for each database driver ID, in
-# a dictionary. A relative (to the working directory for the package)
-# location may be specified, or absolute.
+# a dictionary. Either an absolute or relative path can be specified.
+# In cases where it may be difficult to know what the working directory
+# is, "$DIR" can be specified. This will be replaced with the path to the
+# top-level pgAdmin4.py file. For example, on macOS we might use:
+#
+# $DIR/../../SharedSupport
+#
 ##########################################################################
 DEFAULT_BINARY_PATHS = {
     "pg":   "",

web/pgadmin/browser/server_groups/servers/types.py

@@ -7,7 +7,7 @@
 #
 ##########################################################################
 
-import os
+import os, sys
 
 from flask import render_template
 from flask_babel import gettext as _
@@ -94,7 +94,7 @@ class ServerType(object):
             reverse=True
         )
 
-    def utility(self, operation, sverion):
+    def utility(self, operation, sversion):
         res = None
 
         if operation == 'backup':
@@ -112,10 +112,12 @@ class ServerType(object):
                 ))
             )
 
-        return os.path.join(
-            self.utility_path.get(),
+        bin_path = self.utility_path.get().replace("$DIR", os.path.dirname(sys.modules['__main__'].__file__))
+
+        return os.path.abspath(os.path.join(
+            bin_path,
             (res if os.name != 'nt' else (res + '.exe'))
-        )
+        ))
 
 
 # Default Server Type