I saw a few unexpected glibc test failures after an upgrade to Ubuntu 18.04, which I traced to LD_PRELOAD being set by default (to libgtk3-nocsd.so.0) in the environment, which doesn't work for some glibc tests. Should the testsuite give an obvious error somewhere early for native testing if you have LD_PRELOAD set? -- Joseph S. Myers joseph@codesourcery.com