GLslang: no reuse of shader objects in other program objects?

Based on the spec, there is an aspect of GLslang that I had hoped would be available: that is, linked a shader pair into a new program object when one or both of the pair has previously been linked. I had thought this might be good in order to maximize shader reuse. Unfortunately, it appears that if, for example, a vertex shader has been linked with a fragment shader in one program object, that same vertex shader cannot be linked with another fragment shader in a different program object. Might I be doing something wrong or is this simply impossible?

I’m moving this thread to the shaders forum.