- -- Bleat about errors in the forked thread
- ioToTcRn (do { printErrs (hdr_doc defaultErrStyle) ;
- printErrorsAndWarnings msgs }) ;
+
+ -- Bleat about errors in the forked thread, if -ddump-tc-trace is on
+ -- Otherwise we silently discard errors. Errors can legitimately
+ -- happen when compiling interface signatures (see tcInterfaceSigs)
+ ifOptM Opt_D_dump_tc_trace
+ (ioToTcRn (do { printErrs (hdr_doc defaultErrStyle) ;
+ printErrorsAndWarnings msgs })) ;
+