Depending on what/where the crack is. What type of metal is used in the frame. What kind of sentimental value you have with the handgun.
Some cracks can be repaired, while a lot of other cracks makes it useless.
The other consideration is to get a shadow box and frame the gun (after making sure that it cannot be fired again, even by mistake.)
Bottom line, see a gun smith, and ask him / her of their opinion.
"A well regulated Militia, being necessary to the security of a free State, the right of the people to keep and bear Arms, shall not be infringed."
Life Member NRA
Life Member NAHC
Former President of the ECPT (Eifel Combat Pistol Team)