Currently, the rules for determining the default output name are slightly different between LDC and DMD. This leads to a slight incompatibility regarding LDMD, e.g. breaks the test44.sh script from the DMD testsuite, and possible some custom real-world build systems which do not explicitly specify the output file name.
LDMD should be fixed to follow the same rules as DMD.
could you explicit what is the rule naming when no output name is given to understand what is the difference?