https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63812
--- Comment #4 from Tatsushi Inagaki <e29253 at jp dot ibm.com> --- Ian, Thank you very much for your helpful clarification. I confirmed that the unit test passes with both of GC and GCCGO, when we modify the test from: assertEquals(t, "2.22 PB", HumanSize(2.22*PB)) to: assertEquals(t, "2.22 PB", HumanSize(int64(float64(2.22*PB)))) I will propose this fix to Docker.