CODEWITHSUNDEEP
vb.netwinformsdebugging
ron tornambe
ron tornambe

Reputation: 10780

How to resolve phantom breakpoint?

When I start a debug session, program execution halts at a line that appears to be breakpoint (yellow background color). I must press F5 to continue, and the program proceeds normally.

I call it a phantom breakpoint because no breakpoint appears to be set, and even though executions stops within a loop, I need only press F5 once to proceed.

I tried setting a breakpoint at the phantom location, and removing all breakpoints but to no avail.

The only other similar problems I can find are for Java, and MS-Access where the solution was to de-compile the application.

Although this is very annoying while in development, I was gritting my teeth and baring it until the application was installed on a Citrix server where an error message box is displayed saying that a breakpoint had been encountered.

As an afterthought, I just rebuilt the setup program and after running the application, a critical error was issued. In debug mode, the message was "myapp.exe has triggered a breakpoint:". I cannot explain why it works at all on the Citrix server).

I sure would appreciate any suggestions on how to resolve this issue.

TIA

Upvotes: 3

Views: 876

Answers (1)

Hans Passant
Hans Passant

Reputation: 941505

You are running somebody else's code and that code has an explicit debugger break instruction compiled into the program. You can do so for example by writing Debugger.Break() in a managed program. It could also exist in unmanaged code, the __debugbreak() intrinsic or the DebugBreak() winapi function do this. Could be a simple oversight, it could be that it was intentionally left in the code to warn about a problem.

One way to find the programmer that did this is by using the debugger. Project + Properties, Debug tab, tick the "Enable unmanaged code debugging" option. Then Tools + Options, Debugging, General, untick the "Enable Just My Code" option.

Run the program and reproduce the condition. Now use Debug + Windows + Call Stack and look at the very top of the list. Scroll up if necessary. It might well be grayed out to indicate that this is not your code, it won't be. You'll see the name of a DLL there. Call the company or programmer that wrote that DLL and ask for advice.

Upvotes: 5

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