Semaphores automatically released at end of step??

Testing is showing that semaphores are automatically released at the end of the step that acquires them. Is there not a way that a semaphore can be retained for the duration of a project run (unless explicitly released via .semput)? Re-acquiring the semaphore at the start of each step isn't good enough because there is that race condition where Build 1, Step 1 releases the semaphore and before Build 1, Step 2 can get it back, Build 2, Step 1 grabs it and now build 2 is going to clobber the work of Build 1.