A leaky abstraction colors your approach to solving problems in ways above and beyond what is minimally needed to solve the problem at hand.
For instance, when the author created an HAL instead of a specific problem specific driver, the HAL meant that he had to solve 2 problems instead of 1
The end product had to work, and had to be compatible with the HAL as implemented. The abstraction leaked.
Just making the driver would have yielded a solution to the problem that would"t have required as much refactoring of old code. It's a way of saying he made more work for himself than was necessary.
For instance, when the author created an HAL instead of a specific problem specific driver, the HAL meant that he had to solve 2 problems instead of 1 The end product had to work, and had to be compatible with the HAL as implemented. The abstraction leaked.
Just making the driver would have yielded a solution to the problem that would"t have required as much refactoring of old code. It's a way of saying he made more work for himself than was necessary.
A very YMMV observation.