PASSWORD_QUESTION doesn't hide passwords in Release builds

I build the 5.5 version as
cmake -DCMAKE_BUILD_TYPE=Release
(no additional parameters)

Then I install the plugin 'two_questions' and create a user identified via it.
When I attempt to connect as this user using MySQL client, I get the prompt 'Password, please'. When I type in the password, it's displayed as a usual entry string.

It doesn't happen if I build with CMAKE_BUILD_TYPE=Debug -- the password gets hidden as usual.

It seems to be only the matter of the MySQL client binary -- with the same server and plugins, I get the expected behavior if I use the client binary from the debug build, and erroneous with the client binary from the release build.

Same problem happens on buildbot builds, tried on two different machines, both openSUSE.

Previous releases, e.g. 5.3, seem to work all right (tried the official release build and a buildbot build).

bzr version-info
revision-id: <email address hidden>
date: 2011-12-21 23:40:26 +0100
build-date: 2011-12-22 21:44:25 +0400
revno: 3187
branch-nick: maria-5.5