add sanity check command for Julia + also set $JULIA_DEPOT_PATH

easybuild/easyconfigs/j/Julia/Julia-1.6.0-linux-aarch64.eb

@@ -18,8 +18,17 @@ sources = ['%(namelower)s-%(version)s%(versionsuffix)s.tar.gz']
 checksums = ['0f496972d26cea88151204d03e6bd87702aa1ff983de3b1e4f320c48ef67325f']
 
 sanity_check_paths = {
-    'files': ['bin/julia', 'include/julia/julia.h', 'lib/libjulia.so'],
+    'files': ['bin/julia', 'include/julia/julia.h', 'lib/libjulia.%s' % SHLIB_EXT],
     'dirs': ['bin', 'etc', 'include', 'lib', 'share']
 }
 
+sanity_check_commands = ['julia --help']
+
+modextravars = {
+    # Use default DEPOT_PATH where first entry is user's depot
+    # JULIA_DEPOT_PATH must be set to be able to load other JuliaPackage modules and have
+    # those installations appended to DEPOT_PATH without disabling any of the default paths
+    'JULIA_DEPOT_PATH': ':',
+}
+
 moduleclass = 'lang'