Hi,

At commit 1b321229f4653c5daa873813e24910789c0b2918 (i.e., the current
tip of the core-updates branch), ant-bootstrap@1.7.1 does not build
reproducibly.  This package is defined in gnu/packages/java.scm, but it
is not exported (i.e., it is used privately within the module).  Note
that according to 'guix refresh', currently 215 packages depend on this
package.

To verify that it doesn't build reproducibly, run this command:

  guix build --rounds=2 -e '(@@ (gnu packages java) ant-bootstrap)'

Here's the last bit of output I got:

--8<---------------cut here---------------start------------->8---
output ‘/gnu/store/cl2pxkxrasazj7hb7ykjh895vfj76jfy-ant-bootstrap-1.7.1’ of ‘/gnu/store/9p8yw4cjcb2529gz9l6x4d559xb1qvql-ant-bootstrap-1.7.1.drv’ differs from previous round
@ build-failed /gnu/store/9p8yw4cjcb2529gz9l6x4d559xb1qvql-ant-bootstrap-1.7.1.drv - 1 output ‘/gnu/store/cl2pxkxrasazj7hb7ykjh895vfj76jfy-ant-bootstrap-1.7.1’ of ‘/gnu/store/9p8yw4cjcb2529gz9l6x4d559xb1qvql-ant-bootstrap-1.7.1.drv’ differs from previous round
guix build: error: build failed: build of `/gnu/store/9p8yw4cjcb2529gz9l6x4d559xb1qvql-ant-bootstrap-1.7.1.drv' failed
--8<---------------cut here---------------end--------------->8---

-- 
Chris