• apz28 (37/37) Jan 13 2021 core.exception.InvalidMemoryOperationError@src\core\exception.d(647): In...
• Steven Schveighoffer (17/19) Jan 15 2021 I've struggled with this as well. It doesn't even tell you the original

apz28 <home home.com> writes:

core.exception.InvalidMemoryOperationError src\core\exception.d(647): Invalid
memory operation

reference D runtime unittest executor codes
         try
         {
             fp();
             ++results.passed;
         }
         catch ( Throwable e )
         {
             import core.stdc.stdio;
             printf("%.*s(%llu): [unittest] %.*s\n",
                 cast(int) e.file.length, e.file.ptr, cast(ulong) 
e.line,
                 cast(int) e.message.length, e.message.ptr);

             if ( typeid(e) == typeid(AssertError) )
             {
                 // Crude heuristic to figure whether the 
assertion originates in
                 // the unittested module. TODO: improve.
                 auto moduleName = m.name;
                 if (moduleName.length && e.file.length > 
moduleName.length
                     && e.file[0 .. moduleName.length] == 
moduleName)
                 {
                     // Exception originates in the same module, 
don't print
                     // the stack trace.
                     // TODO: omit stack trace only if assert was 
thrown
                     // directly by the unittest.
                     continue;
                 }
             }
             // TODO: perhaps indent all of this stuff.
             _d_print_throwable(e);
         }

Steven Schveighoffer <schveiguy gmail.com> writes:

On 1/13/21 1:22 PM, apz28 wrote:
 core.exception.InvalidMemoryOperationError src\core\exception.d(647): 
 Invalid memory operation

I've struggled with this as well. It doesn't even tell you the original 
usage point that causes the exception.

I believe stack traces are disabled from printing on this because of the 
fact that it needs some memory to print the trace or walk the trace 
(this is fuzzy, I think it might not need memory, but I can't remember 
exactly).

You can override the handling of memory errors by defining it yourself:

extern(C) void onInvalidMemoryOperationError(void *pretend_sideeffect = 
null)  trusted pure nothrow  nogc
{
    // try to print stack trace here yourself...
}

A very *very* common reason this is triggered is because a GC destructor 
is trying to allocate memory (this is not allowed during GC cleanup). 
But without knowing the trace, it's really hard to find it.

-Steve