libcallback1 binary package in Ubuntu Bionic i386

 ffcall is a collection of libraries which can be used to build
 foreign function call interfaces in embedded interpreters.
 .
 This package installs a shared library version of the callback library, which
 provides closures with variable arguments as first-class C functions.
 .
 The use of this shared library is deprecated. The main libffcall library,
 which embeds callback, should be preferred.

Source package