Sierra games make use of tocgen to create a tOC file. There is in Toolshed a tocgen.exe program but it is envoked in the makefiles with tocgen. This causes a problem with Windows systems and maybe others as tocgen (os9) is confused with tocgen (toolshed) and the makefile fails.
A workaround is to rename or delete the tocgen (os9) file before issuing the makefile tocgen $@,tOC.txt $@,tOC command line. This needs to be individualized for each Sierra game as there are different numbers of disks that require tOC and will change further if DW3 ready disks are added to some of the games.
I don't want to propose a specific solution as the solution may well be dependent on the OS in use to compile the NitrOS-9 project. Windows users can use the msys command mv to rename tocgen (os9) and RM to delete that file. Since tocgen needs to be put in the CMDS directory on the image, it must be present to be copied then removed or renamed prior to generating the tOC file. This must be done for each required disk image.