d++ not working on Redhat 8.10

[nw0428]

When I run d++ *.cpp
I get:

d++: Internal error
<stdin>:1293:86: error: call to undeclared function 'gettid'; ISO C99 and later do not support implicit function declarations [-Wimplicit-function-declaration]
 1293 |     snprintf(threadid_buffer, sizeof threadid_buffer, "DCC_SIGNAL_THREAD=%ld", (long)gettid());
      |                                                                                      ^
1 error generated.

I am using it to compile a simple hello world program so I don't imagine anything in the code is causing it.