diff --git a/common/src/main/java/org/implab/gradle/common/exec/ExecBuilder.java b/common/src/main/java/org/implab/gradle/common/exec/ExecBuilder.java
--- a/common/src/main/java/org/implab/gradle/common/exec/ExecBuilder.java
+++ b/common/src/main/java/org/implab/gradle/common/exec/ExecBuilder.java
@@ -8,6 +8,7 @@ import java.util.Objects;
 import java.util.Optional;
 import java.util.concurrent.CompletableFuture;
 import java.util.stream.Stream;
+import java.util.Collection;
 
 import org.eclipse.jdt.annotation.NonNullByDefault;
 
@@ -31,22 +32,31 @@ public abstract class ExecBuilder {
     private RedirectTo errorRedirect;
 
     /** Sets command line, clears previous one if any */
-    public void command(String cmd, String... args) {
+    public ExecBuilder command(String cmd, String... args) {
         commandLine.clear();
         commandLine.add(cmd);
         Stream.of(args).forEach(commandLine::add);
+        return this;
+    }
+
+    public ExecBuilder command(Collection<String> cmd) {
+        this.commandLine.clear();
+        this.commandLine.addAll(cmd);
+        return this;
     }
 
     /** Adds an argument to the command line */
-    public void argument(String arg) {
+    public ExecBuilder argument(String arg) {
         Objects.requireNonNull(arg, "arg parameter can't be null");
         commandLine.add(arg);
+        return this;
     }
 
     /** Sets the working directory */
-    public void directory(File directory) {
+    public ExecBuilder directory(File directory) {
         Objects.requireNonNull(directory, "directory parameter can't be null");
         this.directory = directory;
+        return this;
     }
 
     /**
@@ -55,14 +65,24 @@ public abstract class ExecBuilder {
      * @param envVar The name of the environment variable
      * @param value  The value to set,
      */
-    public void setEnvironment(String envVar, String value) {
+    public ExecBuilder setEnvironment(String envVar, String value) {
         Objects.requireNonNull(value, "Value can't be null");
         Objects.requireNonNull(envVar, "envVar parameter can't be null");
         environment.put(envVar, value);
+        return this;
     }
 
-    public void unsetEnvironment(String envVar) {
+    public ExecBuilder setEnvironment(Map<String, String> env) {
+        Objects.requireNonNull(env, "env parameter can't be null");
+
+        environment.clear();
+        environment.putAll(env);
+        return this;
+    }
+
+    public ExecBuilder unsetEnvironment(String envVar) {
         environment.remove(envVar);
+        return this;
     }
 
     /**
@@ -72,27 +92,30 @@ public abstract class ExecBuilder {
      * <p>
      * If redirection
      */
-    public void stdin(RedirectFrom from) {
+    public ExecBuilder stdin(RedirectFrom from) {
         Objects.requireNonNull(from, "from parameter can't be null");
         inputRedirect = from;
+        return this;
     }
 
     /**
      * Sets redirection for the stdout, {@link RedirectTo} will be applied
      * every time the process is started.
      */
-    public void stdout(RedirectTo out) {
+    public ExecBuilder stdout(RedirectTo out) {
         Objects.requireNonNull(out, "out parameter can't be null");
         outputRedirect = out;
+        return this;
     }
 
     /**
      * Sets redirection for the stderr, {@link RedirectTo} will be applied
      * every time the process is started.
      */
-    public void stderr(RedirectTo err) {
+    public ExecBuilder stderr(RedirectTo err) {
         Objects.requireNonNull(err, "err parameter can't be null");
         errorRedirect = err;
+        return this;
     }
 
     /** Implement this function to  */