Okay it looks like this is an issue in binutils, not in g++. As stated in the previous comment I installed the version of g++-4.4 and all of its many dependencies that had been used back in 2009-09-18 to build libcrypto++8, and the build still fails. Then I changed binutils from the current (2.20-0ubuntu1) to the 2009-09-18 vintage: 2.19.91.20090910-0ubuntu1 . Now the build passes!
So to reiterate the only change I made in my pbuilder root was to install binutils 2.19.91.20090910-0ubuntu1, replacing binutils 2.20-0ubuntu1, and this made the pbuild of libcrypto++8 go from hanging during the SHA validation to passing.
Okay it looks like this is an issue in binutils, not in g++. As stated in the previous comment I installed the version of g++-4.4 and all of its many dependencies that had been used back in 2009-09-18 to build libcrypto++8, and the build still fails. Then I changed binutils from the current (2.20-0ubuntu1) to the 2009-09-18 vintage: 2.19.91. 20090910- 0ubuntu1 . Now the build passes!
So to reiterate the only change I made in my pbuilder root was to install binutils 2.19.91. 20090910- 0ubuntu1, replacing binutils 2.20-0ubuntu1, and this made the pbuild of libcrypto++8 go from hanging during the SHA validation to passing.