1.53.0 broke ui/consts/const-eval/ub-*.rs tests on s390x (big-endian, 64-bit) (regression) #89577
Description
Probably because s390x is 64-bit big-endian not little-endian, e.g.:
Debian build log, warning several MB
sample
------------------------------------------
diff of 64bit.stderr:
6 |
7 = note: The rules on what exactly is undefined behavior aren't clear, so this check might be overzealous. Please open an issue on the rustc repository if you believe it should not be considered undefined behavior.
8 = note: the raw bytes of the constant (size: 8, align: 8) {
- 01 00 00 00 00 00 00 00 │ ........
+ 00 00 00 00 00 00 00 01 │ ........
10 }
11
12 error[E0080]: it is undefined behavior to use this value
116 |
117 = note: The rules on what exactly is undefined behavior aren't clear, so this check might be overzealous. Please open an issue on the rustc repository if you believe it should not be considered undefined behavior.
118 = note: the raw bytes of the constant (size: 8, align: 4) {
- 78 00 00 00 ff ff ff ff │ x.......
+ 00 00 00 78 ff ff ff ff │ ...x....
120 }
121
122 error[E0080]: it is undefined behavior to use this value
test [ui] ui/consts/const-eval/ub-enum.rs ... FAILED
test [ui] ui/consts/const-eval/ub-int-array.rs ... FAILED
test [ui] ui/consts/const-eval/ub-nonnull.rs ... FAILED
test [ui] ui/consts/const-eval/ub-ref-ptr.rs ... FAILED
test [ui] ui/consts/const-eval/ub-uninhabit.rs ... FAILED
test [ui] ui/consts/const-eval/ub-wide-ptr.rs ... FAILED
These tests were fine in 1.52 so the culprit is probably #76881 @hameerabbasi . I will revert it in Debian for now.