diff --git a/.travis.yml b/.travis.yml
index 931e58835..ff73fb9b4 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -29,7 +29,7 @@ before_install:
 # Not listing Bit::Vector as slow to install, and only skips one test
   - touch temp.cpp ; g++ -E -dM -c temp.cpp | sort ; rm -rf temp.cpp
   - yes yes | sudo cpan -fi Unix::Processors Parallel::Forker
-  - sudo apt-get install gdb gtkwave
+  - sudo apt-get install gdb gtkwave lcov
   - sudo apt-get install libfl-dev || true
   - sudo apt-get install libgoogle-perftools-dev
 before_script:
diff --git a/docs/install.adoc b/docs/install.adoc
index 61d665091..a61171896 100644
--- a/docs/install.adoc
+++ b/docs/install.adoc
@@ -98,7 +98,7 @@ need to be present to run Verilator:
 
 Those developing Verilator itself may also want these (see internals.adoc):
 
-   sudo apt-get install gdb asciidoctor graphviz cmake clang clang-format gprof
+   sudo apt-get install gdb asciidoctor graphviz cmake clang clang-format gprof lcov
    cpan install Pod::Perldoc
    cpan install Unix::Processors
    cpan install Parallel::Forker
diff --git a/nodist/code_coverage b/nodist/code_coverage
index 9659bedbd..4f4cd17d7 100755
--- a/nodist/code_coverage
+++ b/nodist/code_coverage
@@ -12,7 +12,10 @@ use Pod::Usage;
 use strict;
 use vars qw($Debug);
 
+our $Opt_Stop;
 our $Exclude_Line_Regexp;
+our $Remove_Gcda_Regexp;
+
 our @Remove_Sources;
 our @Source_Globs;
 
@@ -27,7 +30,8 @@ Getopt::Long::config("no_auto_abbrev");
 if (! GetOptions(
           "debug"       => sub { $Debug = 1; },
           "<>"          => sub { die "%Error: Unknown parameter: $_[0]\n"; },
-          "stage=i"     => \$Opt_Stage,
+          "stage=i"     => \$Opt_Stage,  # starting stage number
+          "stop!"       => \$Opt_Stop,  # stop/do not stop on error in tests
     )) {
     die "%Error: Bad usage, try 'install_test --help'\n";
 }
@@ -42,45 +46,85 @@ sub test {
     require "./nodist/code_coverage.dat";
 
     if ($Opt_Stage <= 0) {
+        travis_fold_start("configure");
         print "Stage 0: configure (coverage on)\n";
-        run("make distclean");
+        run("make distclean || true");
         run("./configure --enable-longtests CXX='g++ --coverage'");
         run("make -k");
         # The optimized versions will not collect good coverage, overwrite them
         run("cp bin/verilator_bin_dbg bin/verilator_bin");
         run("cp bin/verilator_coverage_bin_dbg bin/verilator_coverage_bin");
+        travis_fold_end();
     }
 
     if ($Opt_Stage <= 1) {
+        travis_fold_start("test");
         print "Stage 1: make examples (with coverage on)\n";
         run("make examples");
-        run("make test_regress");
+        run("make test_regress"
+            . ($Opt_Stop ? '' : ' || true'));
+        travis_fold_end();
     }
 
     my $cc_dir = "nodist/obj_dir/coverage";
     if ($Opt_Stage <= 2) {
+        travis_fold_start("info");
         print "Stage 2: Create info files under $cc_dir\n";
         mkpath($cc_dir);
         mkpath("$cc_dir/info");
         my $dats = `find . -print | grep .gcda`;
-        my %dirs;
+        my %dats;
         foreach my $dat (split '\n', $dats) {
-            $dat =~ s!/[^/]+$!!;
-            $dirs{$dat} = 1;
+            $dats{$dat} = 1;
+        }
+        my %dirs;
+        my %gcnos;
+        foreach my $dat (sort keys %dats) {
+            (my $gcno = $dat) =~ s!\.gcda$!.gcno!;
+            if ($dat =~ /$Remove_Gcda_Regexp/) {
+                # Remove .gcda/.gcno for files we don't care about before we slowly
+                # read them
+                unlink $dat;
+                unlink $gcno;
+                delete $dats{$dat};
+                next;
+            }
+            (my $gbase = $gcno) =~ s!.*/!!;
+            if (!$gcnos{$gbase} && -r $gcno) {
+                $gcnos{$gbase} = $gcno;
+            }
+        }
+        # We need a matching .gcno for every .gcda, try to find a matching file elsewhere
+        foreach my $dat (sort keys %dats) {
+            (my $gcno = $dat) =~ s!\.gcda$!.gcno!;
+            (my $gbase = $gcno) =~ s!.*/!!;
+            if (!-r $gcno) {
+                if ($gcnos{$gbase}) {
+                    cp($gcnos{$gbase}, $gcno);
+                } else {
+                    warn "MISSING .gcno for a .gcda: $gcno\n";
+                }
+            }
+            (my $dir = $dat) =~ s!/[^/]+$!!;
+            $dirs{$dir} = 1;
         }
         foreach my $dir (sort keys %dirs) {
             (my $outname = $dir) =~ s![^a-zA-Z0-9]+!_!g;
             run("cd $cc_dir/info ; lcov -c -d ../../../../$dir -o app_test_${outname}.info");
         }
+        travis_fold_end();
     }
 
     if ($Opt_Stage <= 3) {
+        travis_fold_start("clone");
         # lcov doesn't have a control file to override single lines, so replicate the sources
         print "Stage 3: Clone sources under $cc_dir\n";
         clone_sources($cc_dir);
+        travis_fold_end();
     }
 
     if ($Opt_Stage <= 4) {
+        travis_fold_start("copy");
         print "Stage 4: Copy .gcno files\n";
         my $dats = `find . -print | grep .gcno`;
         foreach my $dat (split '\n', $dats) {
@@ -89,9 +133,11 @@ sub test {
             #print "cp $dat, $outdat);\n";
             cp($dat, $outdat);
         }
+        travis_fold_end();
     }
 
     if ($Opt_Stage <= 5) {
+        travis_fold_start("combine");
         print "Stage 5: Combine data files\n";
         run("cd $cc_dir ; lcov -c -i -d src/obj_dbg -o app_base.info");
         run("cd $cc_dir ; lcov -a app_base.info -o app_total.info");
@@ -106,22 +152,35 @@ sub test {
                 $comb = "";
             }
         }
+        travis_fold_end();
     }
 
     if ($Opt_Stage <= 6) {
+        travis_fold_start("filter");
         print "Stage 6: Filter processed source files\n";
         my $cmd = '';
         foreach my $glob (@Remove_Sources) {
             $cmd .= " '$glob'";
         }
         run("cd $cc_dir ; lcov --remove app_total.info $cmd -o app_total.info");
+        travis_fold_end();
     }
 
-    if ($Opt_Stage <= 7) {
+    if ($Opt_Stage <= 8) {
+        travis_fold_start("report");
         print "Stage 7: Create HTML\n";
         cleanup_abs_paths($cc_dir, "$cc_dir/app_total.info", "$cc_dir/app_total.info");
         run("cd $cc_dir ; genhtml app_total.info --demangle-cpp"
             ." --rc lcov_branch_coverage=1 --rc genhtml_hi_limit=100 --output-directory html");
+        travis_fold_end();
+    }
+
+    if ($Opt_Stage <= 9) {
+        travis_fold_start("upload");
+        print "Stage 9: Upload\n";
+        my $cmd = 'bash <(curl -s https://codecov.io/bash) -f $cc_dir/app_total.info';
+        print "print: Not running: $cmd\n";
+        travis_fold_end();
     }
 
     if ($Opt_Stage <= 9) {
@@ -184,12 +243,13 @@ sub cleanup_abs_paths {
 sub exclude_line_regexp {
     $Exclude_Line_Regexp = shift;
 }
-
+sub remove_gcda_regexp {
+    $Remove_Gcda_Regexp = shift;
+}
 sub remove_source {
     my @srcs = @_;
     push @Remove_Sources, @srcs;
 }
-
 sub source_globs {
     my @dirs = @_;
     push @Source_Globs, @dirs;
@@ -206,6 +266,15 @@ sub run {
     ($status == 0) or die "%Error: Command Failed $command, $status, stopped";
 }
 
+our $_Travis_Action;
+sub travis_fold_start {
+    $_Travis_Action = shift;
+    print "travis_fold:start:$_Travis_Action\n";
+}
+sub travis_fold_end {
+    print "travis_fold:end:$_Travis_Action\n";
+}
+
 #######################################################################
 __END__
 
diff --git a/nodist/code_coverage.dat b/nodist/code_coverage.dat
index 898b65cf7..58e4f8d5e 100644
--- a/nodist/code_coverage.dat
+++ b/nodist/code_coverage.dat
@@ -22,6 +22,7 @@ source_globs("src/*.cpp",
     );
 
 remove_source("/usr/include/*");
+remove_source("/usr/lib/*");
 remove_source("*/include/sysc/*");
 remove_source("*/V3ClkGater.cpp");
 remove_source("*/V3ClkGater.h");
@@ -37,7 +38,10 @@ remove_source("*include/gtkwave/*");
 remove_source("*test_regress/*");
 remove_source("*examples/*");
 
+# Remove collected coverage on each little test main file
+# Would just be removed with remove_source in later step
+remove_gcda_regexp(qr!test_regress/.*/(Vt_|Vtop_).*\.gcda!);
 
-exclude_line_regexp(qr/(\bv3fatalSrc\b|\bVL_UNCOVERABLE\b)/);
+exclude_line_regexp(qr/(\bv3fatalSrc\b|\bVL_UNCOVERABLE\b|\bVL_FATAL)/);
 
 1;
diff --git a/test_regress/driver.pl b/test_regress/driver.pl
index 6163f1b9b..81df6df4d 100755
--- a/test_regress/driver.pl
+++ b/test_regress/driver.pl
@@ -306,6 +306,8 @@ sub new {
         skip_msgs => [],
         fail_msgs => [],
         fail_tests => [],
+        # Per-task identifiers
+        running_ids => {},
         @_};
     bless $self, $class;
     return $self;
@@ -322,14 +324,24 @@ sub one_test {
     $::Fork->schedule
         (
          test_pl_filename => $params{pl_filename},
+         run_pre_start => sub {
+             my $process = shift;
+             # Running in context of parent, before run_on_start
+             # Make an identifier that is unique across all current running jobs
+             my $i = 1; while (exists $self->{running_ids}{$i}) { ++$i; }
+             $process->{running_id} = $i;
+             $self->{running_ids}{$process->{running_id}} = 1;
+         },
          run_on_start => sub {
+             my $process = shift;
              # Running in context of child, so can't pass data to parent directly
              if ($self->{quiet}) {
                  open(STDOUT, ">/dev/null");
                  open(STDERR, ">&STDOUT");
              }
              print("="x70,"\n");
-             my $test = VTest->new(@params);
+             my $test = VTest->new(@params,
+                                   running_id => $process->{running_id});
              $test->oprint("="x50,"\n");
              unlink $test->{status_filename};
              $test->_prep;
@@ -340,7 +352,9 @@ sub one_test {
          },
          run_on_finish => sub {
              # Running in context of parent
-             my $test = VTest->new(@params);
+             my $process = shift;
+             my $test = VTest->new(@params,
+                                   running_id => $process->{running_id});
              $test->_read_status;
              if ($test->ok) {
                  $self->{ok_cnt}++;
@@ -374,6 +388,7 @@ sub one_test {
              }
              $self->{left_cnt}--;
              $self->print_summary;
+             delete $self->{running_ids}{$process->{running_id}};
          },
          )->ready();
 }
@@ -1062,6 +1077,7 @@ sub compile {
                         tee => $param{tee},
                         expect => $param{expect},
                         expect_filename => $param{expect_filename},
+                        verilator_run => 1,
                         cmd => \@vlt_cmd) if $::Opt_Verilation;
             return 1 if $self->errors || $self->skips || $self->unsupporteds;
         }
@@ -1077,6 +1093,7 @@ sub compile {
                         tee => $param{tee},
                         expect => $param{expect},
                         expect_filename => $param{expect_filename},
+                        verilator_run => 1,
                         cmd => ["cd \"".$self->{obj_dir}."\" && cmake",
                                 "\"".$self->{t_dir}."/..\"",
                                 "-DTEST_VERILATOR_ROOT=$ENV{VERILATOR_ROOT}",
@@ -1458,6 +1475,7 @@ sub _run {
     my $self = (ref $_[0]? shift : $Self);
     my %param = (tee => 1,
                  #entering =>  # Print entering directory information
+                 #verilator_run =>  # Move gcov data to parallel area
                  @_);
     my $command = join(' ',@{$param{cmd}});
     $command = "time $command" if $opt_benchmark && $command !~ /^cd /;
@@ -1465,6 +1483,17 @@ sub _run {
     print "   > $param{logfile}" if $param{logfile};
     print "\n";
 
+    if ($param{verilator_run}) {
+        # Gcov fails when parallel jobs write same data file,
+        # so we make sure output dir is unique across all running jobs.
+        # We can't just put each one in obj_dir as it uses too much disk.
+        $ENV{GCOV_PREFIX_STRIP} = 99;
+        $ENV{GCOV_PREFIX} = "$self->{t_dir}/obj_dist/gcov_$self->{running_id}";
+    } else {
+        delete $ENV{GCOV_PREFIX_STRIP};
+        delete $ENV{GCOV_PREFIX};
+    }
+
     # Execute command redirecting output, keeping order between stderr and stdout.
     # Must do low-level IO so GCC interaction works (can't be line-based)
     my $status;
@@ -2271,6 +2300,7 @@ sub schedule {
     my $self = shift;
     my %params = (@_);
 
+    $params{run_pre_start}->($self);
     if (my $pid = fork()) {  # Parent
         waitpid($pid, 0);
     } else {  # Child
diff --git a/test_regress/t/t_a1_first_cc.pl b/test_regress/t/t_a1_first_cc.pl
index 9e03d8e8a..50fc6fcd9 100755
--- a/test_regress/t/t_a1_first_cc.pl
+++ b/test_regress/t/t_a1_first_cc.pl
@@ -16,7 +16,9 @@ scenarios(simulator => 1);
 
 $DEBUG_QUIET = "--debug --debugi 0 --gdbbt --no-dump-tree";
 
-run(cmd => ["perl", "../bin/verilator", $DEBUG_QUIET, "-V"]);
+run(cmd => ["perl", "../bin/verilator", $DEBUG_QUIET, "-V"],
+    verilator_run => 1,
+    );
 
 compile(
     verilator_flags2 => [$DEBUG_QUIET, "--trace"],
diff --git a/test_regress/t/t_cover_line_cc.pl b/test_regress/t/t_cover_line_cc.pl
index 8782e89bb..563ce9ffd 100755
--- a/test_regress/t/t_cover_line_cc.pl
+++ b/test_regress/t/t_cover_line_cc.pl
@@ -25,8 +25,9 @@ inline_checks();
 
 run(cmd => ["../bin/verilator_coverage",
             "--annotate", "$Self->{obj_dir}/annotated",
-            "$Self->{obj_dir}/coverage.dat",
-    ]);
+            "$Self->{obj_dir}/coverage.dat"],
+    verilator_run => 1,
+    );
 
 files_identical("$Self->{obj_dir}/annotated/t_cover_line.v", "t/t_cover_line.out");
 
diff --git a/test_regress/t/t_cover_line_cc_vlt.pl b/test_regress/t/t_cover_line_cc_vlt.pl
index 3b1a9ddff..1d21931e1 100755
--- a/test_regress/t/t_cover_line_cc_vlt.pl
+++ b/test_regress/t/t_cover_line_cc_vlt.pl
@@ -26,7 +26,9 @@ inline_checks();
 run(cmd => ["../bin/verilator_coverage",
             "--annotate", "$Self->{obj_dir}/annotated",
             "$Self->{obj_dir}/coverage.dat",
-    ]);
+            ],
+    verilator_run => 1,
+    );
 
 files_identical("$Self->{obj_dir}/annotated/t_cover_line.v", "t/t_cover_line.out");
 
diff --git a/test_regress/t/t_cover_line_trace.pl b/test_regress/t/t_cover_line_trace.pl
index adf5699f7..a3763b8c5 100755
--- a/test_regress/t/t_cover_line_trace.pl
+++ b/test_regress/t/t_cover_line_trace.pl
@@ -23,7 +23,9 @@ execute(
 run(cmd => ["../bin/verilator_coverage",
             "--annotate", "$Self->{obj_dir}/annotated",
             "$Self->{obj_dir}/coverage.dat",
-    ]);
+    ],
+    verilator_run => 1,
+    );
 
 files_identical("$Self->{obj_dir}/annotated/t_cover_line.v", "t/t_cover_line.out");
 vcd_identical("$Self->{obj_dir}/simx.vcd", $Self->{golden_filename});
diff --git a/test_regress/t/t_flag_help.pl b/test_regress/t/t_flag_help.pl
index 12f95bee3..f3dc0cca4 100755
--- a/test_regress/t/t_flag_help.pl
+++ b/test_regress/t/t_flag_help.pl
@@ -23,6 +23,7 @@ foreach my $prog (
                 "--help"],
         logfile => "$Self->{obj_dir}/t_help.log",
         tee => 0,
+        verilator_run => 1,
         );
     file_grep("$Self->{obj_dir}/t_help.log", qr/DISTRIBUTION/i);
 }
diff --git a/test_regress/t/t_flag_version.pl b/test_regress/t/t_flag_version.pl
index 571a4904e..2b145b855 100755
--- a/test_regress/t/t_flag_version.pl
+++ b/test_regress/t/t_flag_version.pl
@@ -24,6 +24,7 @@ foreach my $prog (
         tee => $self->{verbose},
         logfile => "$Self->{obj_dir}/t_help.log",
         expect => qr/^Verilator/,
+        verilator_run => 1,
         );
 
     run(fails => 0,
@@ -32,6 +33,7 @@ foreach my $prog (
         tee => $self->{verbose},
         logfile => "$Self->{obj_dir}/t_help.log",
         expect => qr/^Verilator/,
+        verilator_run => 1,
         );
 
     run(fails => 0,
@@ -39,6 +41,7 @@ foreach my $prog (
                 "-V"],
         logfile => "$Self->{obj_dir}/t_help.log",
         expect => qr/^Verilator/,
+        verilator_run => 1,
         );
 }
 
diff --git a/test_regress/t/t_gantt.pl b/test_regress/t/t_gantt.pl
index 80b72c677..e38cd63b7 100755
--- a/test_regress/t/t_gantt.pl
+++ b/test_regress/t/t_gantt.pl
@@ -40,7 +40,9 @@ execute(
 run(cmd => ["$ENV{VERILATOR_ROOT}/bin/verilator_gantt",
             "$Self->{obj_dir}/profile_threads.dat",
             "--vcd $Self->{obj_dir}/profile_threads.vcd",
-            "> $Self->{obj_dir}/gantt.log"]);
+            "> $Self->{obj_dir}/gantt.log"],
+    verilator_run => 1,
+    );
 
 # We should have three lines of gantt chart, each with
 # an even number of mtask-bars (eg "[123--]")
diff --git a/test_regress/t/t_lint_only.pl b/test_regress/t/t_lint_only.pl
index 06fd4329a..d1e2ac8bc 100755
--- a/test_regress/t/t_lint_only.pl
+++ b/test_regress/t/t_lint_only.pl
@@ -13,8 +13,9 @@ scenarios(vlt => 1);
 lint();
 
 foreach my $file (glob("$Self->{obj_dir}/*")) {
-    next if $file =~ /\.log/;  # Made by driver.pl, not Verilator
-    next if $file =~ /\.status/;  # Made by driver.pl, not Verilator
+    next if $file =~ /\.log/;  # Made by driver.pl, not Verilator sources
+    next if $file =~ /\.status/;  # Made by driver.pl, not Verilator sources
+    next if $file =~ /\.gcda/;  # Made by gcov, not Verilator sources
     error("%Error: Created $file, but --lint-only shouldn't create files");
 }
 
diff --git a/test_regress/t/t_prot_lib.pl b/test_regress/t/t_prot_lib.pl
index 441859d33..7f79aaf76 100755
--- a/test_regress/t/t_prot_lib.pl
+++ b/test_regress/t/t_prot_lib.pl
@@ -35,7 +35,9 @@ while (1) {
                 $secret_dir,
                 "--protect-lib",
                 $secret_prefix,
-                "t/t_prot_lib_secret.v"]);
+                "t/t_prot_lib_secret.v"],
+        verilator_run => 1,
+        );
     last if $Self->{errors};
 
     run(logfile => "$secret_dir/secret_gcc.log",
diff --git a/test_regress/t/t_prot_lib_clk_gated.pl b/test_regress/t/t_prot_lib_clk_gated.pl
index fd97a715a..f271e3cbb 100755
--- a/test_regress/t/t_prot_lib_clk_gated.pl
+++ b/test_regress/t/t_prot_lib_clk_gated.pl
@@ -37,7 +37,9 @@ while (1) {
                 "-GGATED_CLK=1",
                 "--protect-lib",
                 $secret_prefix,
-                "t/t_prot_lib_secret.v"]);
+                "t/t_prot_lib_secret.v"],
+        verilator_run => 1,
+        );
     last if $Self->{errors};
 
     run(logfile => "$secret_dir/secret_gcc.log",
diff --git a/test_regress/t/t_vlcov_debugi.pl b/test_regress/t/t_vlcov_debugi.pl
index 0600b969f..8cc5f0d57 100755
--- a/test_regress/t/t_vlcov_debugi.pl
+++ b/test_regress/t/t_vlcov_debugi.pl
@@ -20,6 +20,7 @@ foreach my $basename ("t_vlcov_data_a.dat",
                 "--debugi 9",
         ],
         tee => $Self->{verbose},
+        verilator_run => 1,
         );
 }
 
diff --git a/test_regress/t/t_vlcov_merge.pl b/test_regress/t/t_vlcov_merge.pl
index 8f92b7eb4..181c9ecbd 100755
--- a/test_regress/t/t_vlcov_merge.pl
+++ b/test_regress/t/t_vlcov_merge.pl
@@ -16,7 +16,9 @@ run(cmd => ["../bin/verilator_coverage",
             "t/t_vlcov_data_b.dat",
             "t/t_vlcov_data_c.dat",
             "t/t_vlcov_data_d.dat",
-    ]);
+    ],
+    verilator_run => 1,
+    );
 
 # Older clib's didn't properly sort maps, but the coverage data doesn't
 # really care about ordering. So avoid false failures by sorting.
diff --git a/test_regress/t/t_vlcov_nfound_bad.pl b/test_regress/t/t_vlcov_nfound_bad.pl
index fc34cc0cf..e38aabd39 100755
--- a/test_regress/t/t_vlcov_nfound_bad.pl
+++ b/test_regress/t/t_vlcov_nfound_bad.pl
@@ -15,6 +15,7 @@ run(fails => 1,
             "t/t_NOT_FOUND",],
     logfile => $Self->{run_log_filename},
     expect_filename => $Self->{golden_filename},
+    verilator_run => 1,
     );
 
 ok(1);
diff --git a/test_regress/t/t_vlcov_rank.pl b/test_regress/t/t_vlcov_rank.pl
index fdcbb8e79..ca5917c16 100755
--- a/test_regress/t/t_vlcov_rank.pl
+++ b/test_regress/t/t_vlcov_rank.pl
@@ -19,6 +19,7 @@ run(cmd => ["../bin/verilator_coverage",
     ],
     logfile => "$Self->{obj_dir}/vlcov.log",
     tee => 0,
+    verilator_run => 1,
     );
 
 files_identical("$Self->{obj_dir}/vlcov.log", $Self->{golden_filename});
diff --git a/test_regress/t/t_vlcov_rewrite.pl b/test_regress/t/t_vlcov_rewrite.pl
index c3c4543a2..6611d4e00 100755
--- a/test_regress/t/t_vlcov_rewrite.pl
+++ b/test_regress/t/t_vlcov_rewrite.pl
@@ -20,6 +20,7 @@ foreach my $basename ("t_vlcov_data_a.dat",
                 "--write", "$Self->{obj_dir}/${basename}"
         ],
         tee => 0,
+        verilator_run => 1,
         );
     files_identical("$Self->{obj_dir}/${basename}", "t/${basename}");
 }