gap-4.4.12 -- workspaces broken on iras (itanium Linux)

[williamstein]

Saving workspaces is broken in GAP SUSE Itanium.

sage: !gap
    
            #########           ######         ###########           ###  
         #############          ######         ############         ####  
        ##############         ########        #############       #####  
       ###############         ########        #####   ######      #####  
      ######         #         #########       #####    #####     ######  
     ######                   ##########       #####    #####    #######  
     #####                    ##### ####       #####   ######   ########  
     ####                    #####  #####      #############   ###  ####  
     #####     #######       ####    ####      ###########    ####  ####  
     #####     #######      #####    #####     ######        ####   ####  
     #####     #######      #####    #####     #####         #############
      #####      #####     ################    #####         #############
      ######     #####     ################    #####         #############
      ################    ##################   #####                ####  
       ###############    #####        #####   #####                ####  
         #############    #####        #####   #####                ####  
          #########      #####          #####  #####                ####  
                                                                          
     Information at:  http://www.gap-system.org
     Try '?help' for help. See also  '?copyright' and  '?authors'
    
   Loading the library. Please be patient, this may take a while.
GAP4, Version: 4.4.12 of 17-Dec-2008, ia64-unknown-linux-gnu-gcc
gap> SaveWorkspace("a");
true
gap>
wstein@iras:/tmp/wstein/sage-3.4.alpha0-ia64-Linux/x> ls
?ǎ?

Component: packages: standard

Issue created by migration from https://trac.sagemath.org/ticket/5455

[williamstein]

Description changed:

--- 
+++ 
@@ -1,4 +1,4 @@
-Saving and loading workspaces is broke in gap Itanium (SUSE). Also, loading of any packages is now mysteriously broken:
+Saving workspaces is broken in GAP SUSE Itanium. 
 
 ```
 sage: !gap
@@ -26,6 +26,9 @@
     
    Loading the library. Please be patient, this may take a while.
 GAP4, Version: 4.4.12 of 17-Dec-2008, ia64-unknown-linux-gnu-gcc
-gap> LoadPackage("braid");
-fail
+gap> SaveWorkspace("a");
+true
+gap>
+wstein@iras:/tmp/wstein/sage-3.4.alpha0-ia64-Linux/x> ls
+?ǎ?
 ```

[williamstein]

comment:2

Basically the filename option to SaveWorkspace seems to be randomly corrupted.

[williamstein]

comment:3

Attachment: trac_5455.patch.gz

I've posted a patch that just disables the workspace caching optimization completely for Itanium. I wrote workspace caching for gap (long ago) and it is 100% just an optimization -- things should be functionally equivalent but just the first time one does "gap(...)" it is slower.

NOTE: I also tried compiling gap with -O0 and that didn't fix this problem.

[williamstein]

comment:4

I'm testing my patch. I noticed that this fails:

File "/home/wstein/iras/build/sage-3.4.alpha0/devel/sage/doc/en/constructions/linear_codes.rst", line 29:
    sage: C.minimum_distance()
Exception raised:
    RuntimeError: Gap produced error output
    Variable: 'GeneratorMatCode' must have a value

I'm guessing the problem is that when use_workspace_cache is False, then certain packages don't get loaded, maybe. This would be another separate bug in the gap interface.

[sagetrac-mabshoff]

comment:5

Positive review.

Cheers,

Michael