document that the `-var-file` option still expects JSON files for now

command/build.go

@@ -419,7 +419,7 @@ Options:
   -parallel-builds=1            Number of builds to run in parallel. 0 means no limit (Default: 0)
   -timestamp-ui                 Enable prefixing of each ui output with an RFC3339 timestamp.
   -var 'key=value'              Variable for templates, can be used multiple times.
-  -var-file=path                JSON file containing user variables.
+  -var-file=path                JSON file containing user variables. [ Note that even in HCL mode this expects file to contain JSON, a fix is comming soon ]
 `
 
 	return strings.TrimSpace(helpText)

command/console.go

@@ -92,7 +92,7 @@ Usage: packer console [options] [TEMPLATE]
 
 Options:
   -var 'key=value'       Variable for templates, can be used multiple times.
-  -var-file=path         JSON file containing user variables.
+  -var-file=path         JSON file containing user variables. [ Note that even in HCL mode this expects file to contain JSON, a fix is comming soon ]
 `
 
 	return strings.TrimSpace(helpText)

command/validate.go

@@ -183,7 +183,7 @@ Options:
   -except=foo,bar,baz    Validate all builds other than these.
   -only=foo,bar,baz      Validate only these builds.
   -var 'key=value'       Variable for templates, can be used multiple times.
-  -var-file=path         JSON file containing user variables.
+  -var-file=path         JSON file containing user variables. [ Note that even in HCL mode this expects file to contain JSON, a fix is comming soon ]
 `
 
 	return strings.TrimSpace(helpText)