Unable to set watchpoint

Unable to set watchpoint

I've encountered a problem that appears to have arisen sometime in the last year with the debugger when trying to set a watchpoint on a Fortran variable:

Intel(R) Debugger for applications running on Intel(R) 64, Build [74.923.2]

(idb) whatis TESTVAR

type = COMPLEX(8) (64,800,6)

(idb) watch TESTVAR(36,326,1)

Watchpoint 2: TESTVAR(36, 326, 1)

However, with the newer version, I am unable to set a watchpoint:

Intel(R) Debugger for applications running on Intel(R) 64, Build [79.936.23]

(idb) whatis TESTVAR

type = COMPLEX(8)

(idb) watch TESTVAR(36,326,1)

could not insert watchpoint because its size is not supported as requested

Watchpoint remains disabled. It can be enabled later once the error condition is resolved.


Note the improper size being reported with the "whatis" statement.  In both instances, I am debugging the same executable (which was built using compiler version 12.0.4), so it definitely appears to be debugger-related.

Thanks in advance.

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Hi ereisch,

in later versions of IDB the watch statements use hardware watch points. These unfortunately do not support all variable sizes, hence the error message you are experiencing. This is discussed in the release notes where you can find more details.

Since IDB has been deprecated I suggest to move on to GDB that is included in e.g. in Composer XE 2013 SP1

Many Thanks,


Well, even though the tool is deprecated, I'm sure most people would disagree with the concept of adding features that reduce functionality....I guess for the time being I will have to resort to using the 2012 version of the debugger.

Is there a details page available somewhere on the new debugger?  I haven't been able to find one.  I did hear, however, that Intel was going to be adding functionality to an open-source debugger instead of maintaining their own; while I think this is an excellent idea, the GUI frontends to the gdb debugger leave a lot to be desired and I, for one, very much appreciated the look and feel of the "packaged" debugger/GUI product intel provided in IDB.  Since it is presumably open-source, is it possible to download this debugger as a standalone package, or do you have to purchase/download the compiler suite to get it?  And does it come with a GUI frontend or is it only the command-line version that's available?



The team working on GDB at Intel makes the changes available in packages such as Intel System Studio and then upstreams those to the GDB project. 

On http://intel-gdb.github.io/ is an example of the work we are currently doing around Fortran variable length array support. Feel free to experiment with some of the repository contents -  I am sure the team welcomes your feedback!

GDB can be used from the command line or within eclipse.

If you want to try this our you can download and install the Intel(R) System Studio 2014 BETA version free of cost from here: http://software.intel.com/en-us/intel-system-studio-beta/

Here is a snippet from the GDB release notes on new features on top of GDB 7.5 (what I currently happen to have installed)

  • Data Race Detection (pdbx): Detect and locate data races for applications threaded using POSIX* thread (pthread) or OpenMP* models
  • Branch Trace Store (btrace): Record branches taken in the execution flow to backtrack easily after events like crashes, signals, exceptions, etc.
  • Pointer Checker: Assist in finding pointer issues if compiled with IntelR C++ Compiler and having Pointer Checker feature enabled (see Intel C++ Compiler documentation for more information)
  • GDB remote debug integration into Eclipse* CDT


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