Fix: message error '--build-tools=BUILD_TOOL_NAME' (#303)

Author: marcel-dias

lsif-java/src/main/scala/com/sourcegraph/lsif_java/commands/IndexCommand.scala

@@ -163,7 +163,7 @@ case class IndexCommand(
         val names = many.map(_.name).mkString(", ")
         app.error(
           s"Multiple build tools detected: $names. " +
-            s"To fix this problem, use the '--build-tools=BUILD_TOOL_NAME' flag to specify which build tool to run."
+            s"To fix this problem, use the '--build-tool=BUILD_TOOL_NAME' flag to specify which build tool to run."
         )
         1
     }

tests/buildTools/src/test/scala/tests/MissingBuildToolSuite.scala

@@ -14,7 +14,7 @@ class MissingBuildToolSuite extends BaseBuildToolSuite {
     "ambiguous",
     List("index"),
     expectedOutput =
-      """|error: Multiple build tools detected: Gradle, Maven. To fix this problem, use the '--build-tools=BUILD_TOOL_NAME' flag to specify which build tool to run.
+      """|error: Multiple build tools detected: Gradle, Maven. To fix this problem, use the '--build-tool=BUILD_TOOL_NAME' flag to specify which build tool to run.
          |""".stripMargin,
     workingDirectoryLayout =
       """|/pom.xml