Hi, all I posted this question yesterday, and get no answer. Let me to be more specific this time. I try to build a TK1 ARM VMM image from the source code SEL4PROJ/camkes-vm-manifest in GitHub. However, I can not compile it. I get errors when the compiler tries to parse capDL. The errors are appended as follows: " make: Entering directory '/home/dev/Documents/new_vmm/projects/capd /capDL-tool' stack setup make: stack: Command not found Makefile:37: recipe for target 'sandbox' failed make: *** [sandbox] Error 127 make: Leaving directory '/home/dev/Documents/new_vmm/projects/capdl/capDL-tool' Makefile:51: recipe for target '/home/dev/Documents/new_vmm/stage/arm/tk1/parse-capDL/parse-capDL' failed " I checked that there is a file called stack.ymal in the directory: ~/capdl/capDL-tool. My system is also installed latest ghc and ghc-prof. Anybody can help me on this problem? Thanks Peng