ALPACA requires Celera Assembler 8.3 or later. It is recommended to build Celera Assembler from source. (Why? The pre-built binaries CA_8.3rc1 and CA8.3rc2 will work for any large data set.
Detail paper at https://bmcgenomics.biomedcentral.com/articles/10.1186/s12864-017-3927-8