-include ../tools.mk all: cp foo.rs $(TMPDIR) cd $(TMPDIR) -$(RUSTC) -Z unstable-options --error-format=json foo.rs 2>foo.log grep -q '{"message":"unresolved name `y`","code":{"code":"E0425","explanation":"\\nAn unresolved name was used. Example of erroneous codes.*"},"level":"error","spans":\[{"file_name":"foo.rs","byte_start":496,"byte_end":497,"line_start":12,"line_end":12,"column_start":18,"column_end":19}\],"children":\[\]}' foo.log grep -q '{"message":".*","code":{"code":"E0277","explanation":"\\nYou tried.*"},"level":"error","spans":\[{.*}\],"children":\[{"message":"the .*","code":null,"level":"help","spans":\[{"file_name":"foo.rs","byte_start":504,"byte_end":516,"line_start":14,"line_end":14,"column_start":0,"column_end":0}\],"children":\[\]},{"message":" ","code":null,"level":"help",' foo.log