When I tried to build the latest ncdu version (058b26bf9a), the following error occured:
./src/main.zig:345:38: error: expected error union type, found 'std.child_process.ChildProcess'
var child = std.ChildProcess.init(&.{shell}, allocator) catch unreachable;
It's due to commit a0a2ce9, which quote "std: Do not allocate the result for ChildProcess.init"
A patch is provided that will hopefully still work by the time of the Zig 0.10 release.