CRYPTOPP_COVERAGE was added at 9614307ab7 to increase code coverage support. This commit enables additional validation routines when CRYPTOPP_COVERAGE is in effect.
regtest.cpp is where ciphers register by name. The library has added a number of ciphers over the last couple of years and the source file has experienced bloat. Most of the ARM and MIPS test borads were suffering Out of Memory (OOM) kills as the compiler processed the source fille and the included header files.
This won't stop the OOM kills, but it will help the situation. An early BeagleBoard with 512 MB of RAM is still going to have trouble, but it can be worked around by building with 1 make job as opposed to 2 or 4.
Jeffrey Walton