message: Don't use tcmalloc in debug binary.
  It interferes badly with valgrind.
  Fixes:
diff: @@ -37,7 +37,7 @@ run-cmake-release_no_tcmalloc:
  cmake -DNO_TCMALLOC=On -DCMAKE_BUILD_TYPE=Release -DCMAKE_INSTALL_PREFIX=$(PREFIX) -DCMAKE_RULE_MESSAGES=$(RULE_MESSAGES) -S . -B build
  run-cmake-debug:
  - cmake -DCMAKE_BUILD_TYPE=Debug -DCMAKE_INSTALL_PREFIX=$(PREFIX) -DCMAKE_RULE_MESSAGES=$(RULE_MESSAGES) -S . -B dbuild
  + cmake -DCMAKE_BUILD_TYPE=Debug -DCMAKE_INSTALL_PREFIX=$(PREFIX) -DCMAKE_RULE_MESSAGES=$(RULE_MESSAGES) -DNO_TCMALLOC=On -S . -B dbuild
  run-cmake-coverage:
  cmake -DCMAKE_BUILD_TYPE=Debug -DCMAKE_INSTALL_PREFIX=$(PREFIX) -DCMAKE_RULE_MESSAGES=$(RULE_MESSAGES) -DMY_CXX_WARNING_FLAGS="--coverage" -S . -B coverage-build
  