Failure to load h5mma results in hanging during package load

[Ian Hinder]

When launching h5mma from Mathematica, a failure to load the executable (e.g. a segfault or missing dynamic library) manifests itself as a hang in the frontend. This can be interrupted, but an error message would be much better.

If we cannot detect the failure somehow (and this might be a limitation of mathlink) we can use TimeConstrained to time out after 10s or so. Better would be to detect the error message somehow and report it to the user.

[Barry Wardell]

Usually when the binary fails to load, Install[...] returns $Failed and we report an error in such a case. It looks like there are cases where Install never returns. This seems to happen when there is a binary there, but it's not working. I think your TimeConstrained suggestion is probably the best option in this case. How about the following patch:

diff --git a/h5mma.m b/h5mma.m
index 9089aad..ece02a2 100644
--- a/h5mma.m
+++ b/h5mma.m
@@ -45,10 +45,10 @@ Module[{installed},
       installed = Install[p1 <> "@" <> host <> "," <> p2 <> "@" <> host, LinkMode -> Connect, LinkProtocol -> "TCPIP"];
     ]
   ,
-    installed = Install["h5mma"];
+    installed = TimeConstrained[Install["h5mma"], 10];
   ];

-  If[installed === $Failed,
+  If[installed === $Failed || installed === $Aborted,
     Print["h5mma has been installed but the MathLink executable cannot be loaded. Check the README file for instructions on compiling it."];
     Abort[];
   ];

[Ian Hinder]

Looks good, though we might want to change the error message suggesting that they compile it. We could have a list of possible reasons and their fixes, but isn't compiling it quite complicated?

[Barry Wardell]

This has been fixed in 5d1f21fbb413fec1334f478661c150270db79961 and 48bc129b546931d971066caee9e3b96169c88abb.