This reverts commit 62765608.
as this is breaking on boost < 1.73

ref. https://github.com/boostorg/test/commit/235acea2fa4b1eb7580acbfcce94d696c86bb207#diff-9131a06d2a1a6d0c877c9b7909acbbde

Fix debug-tracer.cpp

Renamed tracer.cpp in debug-tracer.cpp

pool.cpp: test exception catching.