Recency checks (#609)

---------

Co-authored-by: Michael Ernst <[email protected]>

README.md

@@ -64,6 +64,30 @@ Each bug has the following properties:
 The (b)uggy and (f)ixed program revisions are labelled with `<id>b` and
 `<id>f`, respectively (`<id>` is an integer).
 
+Reproducibility
+================
+
+#### Java version
+All bugs have been reproduced and triggering tests verified, using the latest
+version of Java 11.
+Using a different version of Java might result in unexpected failing tests
+and/or non-reproducible bugs.
+
+#### Locale
+Defects4J uses the JDK-8 compatible locale service provider to ensure
+reproducibility of bugs.
+
+If you are using the bugs _outside_ of the Defects4J framework, [set the
+JVM's locale service provider to
+COMPAT](https://docs.oracle.com/en%2Fjava%2Fjavase%2F11%2Fdocs%2Fapi%2F%2F/java.base/java/util/spi/LocaleServiceProvider.html)
+Specifically, use `java -Djava.locale.providers=COMPAT` to ensure
+reproducibility. Not setting this option results in unexpected failing tests!
+
+#### Timezone
+Defects4J generates and executes tests in the timezone `America/Los_Angeles`.
+
+If you are using the bugs _outside_ of the Defects4J framework, set the `TZ`
+environment variable to `America/Los_Angeles` and export it.
 
 Setting up Defects4J
 ================
@@ -77,19 +101,9 @@ Requirements
  - `cpanm`
 
 Defects4J version 2.x required Java 1.8.
-Defects4J version 1.x and 0.x required Java 1.7.
-
 
-#### Java version
-All bugs have been reproduced and triggering tests verified, using the latest
-version of Java 11.
-Using a different version of Java might result in unexpected failing tests on a fixed
-program version. 
+Defects4J version 1.x and 0.x required Java 1.7.
 
-#### Timezone
-Defects4J generates and executes tests in the timezone `America/Los_Angeles`.
-If you are using the bugs outside of the Defects4J framework, set the `TZ`
-environment variable to `America/Los_Angeles` and export it.
 
 #### Perl dependencies
 All required Perl modules are listed in [cpanfile](https://github.com/rjust/defects4j/blob/master/cpanfile).

framework/bug-mining/create-project.pl

@@ -160,5 +160,6 @@ =head1 DESCRIPTION
 close(OUT);
 
 # Clone the repository
-system("mkdir -p $repo_dir && git clone --bare $URL $repo_dir/$NAME.git 2>&1"
-        . " && echo $NAME: Cloned from $URL >> $repo_dir/README") == 0 or die "Failed to clone repository";
+Utils::exec_cmd("mkdir -p $repo_dir && cp $REPO_DIR/README $repo_dir", "Prepare repository directory");
+Utils::exec_cmd("git clone --bare $URL $repo_dir/$NAME.git 2>&1", "Clone repository from $URL");
+Utils::exec_cmd("echo $NAME: Cloned from $URL >> $repo_dir/README", "Update repository metadata");

framework/core/Constants.pm

@@ -245,22 +245,29 @@ if ($java_version_output =~ 'version "?(?:1\.)?(\K\d+)') {
 # - External libraries (test generation) available?
 #
 _repos_available()
-        or die("Couldn't find project repositories! Did you (re)run 'defects4j/init.sh'?\n\n");
+        or die("Couldn't find up-to-date project repositories! Did you (re)run 'defects4j/init.sh'?\n\n");
+
 -e "$MAJOR_ROOT/bin/ant"
         or die("Couldn't find Major mutation framework! Did you (re)run 'defects4j/init.sh'?\n\n");
+
 -d "$TESTGEN_LIB_DIR"
         or die("Couldn't find test generation tools! Did you (re)run 'defects4j/init.sh'?\n\n");
+
 -d "$BUILD_SYSTEMS_LIB_DIR"
         or die("Couldn't find build system tools! Did you (re)run 'defects4j/init.sh'?\n\n");
+
 -d "$BUILD_SYSTEMS_LIB_DIR/gradle/dists"
         or die("Couldn't find gradle distributions! Did you (re)run 'defects4j/init.sh'?\n\n");
+
 -d "$BUILD_SYSTEMS_LIB_DIR/gradle/deps"
         or die("Couldn't find gradle dependencies! Did you (re)run 'defects4j/init.sh'?\n\n");
 
 sub _repos_available {
-    opendir(my $dh, "$REPO_DIR") or die "Cannot read $REPO_DIR: $!";
-    # The repos directory by default only contains a helper script
-    return scalar(grep { $_ ne "." && $_ ne ".." } readdir($dh)) > 1;
+    -e "$REPO_DIR/README" or return 0;
+    open(IN, "<$REPO_DIR/README") or return 0;
+    my $line = <IN>;
+    close(IN);
+    $line =~ /Defects4J version 3/ or return 0;
 }
 
 # Add script and core directory to @INC