see https://docs.travis-ci.com/user/customizing-the-build#Git-Clone-Depth

Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
---
 .travis.yml | 1 +
 1 file changed, 1 insertion(+)

diff --git a/.travis.yml b/.travis.yml
index 57462b0471..72aad5ca35 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -70,6 +70,7 @@ env:
     - CONFIG="--with-coroutine=sigaltstack"
     - CONFIG="--enable-debug --enable-debug-tcg --enable-trace-backends=log"
 git:
+  depth: 3
   # we want to do this ourselves
   submodules: false
 before_install:
-- 
2.13.3