Don't use `-fsanitize-trap`

The `-fsanitize-trap` option turns diagnosable runtime errors into illegal instruction exceptions [[1](https://clang.llvm.org/docs/UndefinedBehaviorSanitizer.html#usage), [2](https://maskray.me/blog/2023-01-29-all-about-undefined-behavior-sanitizer#trap-mode)] which are much less informative without an interactive debugger (in a typical GitHub Action context). For example: 1. With default options, pointer arithmetic on a null pointer crashes the process without any diagnostic: ``` $ podman run --rm -it ghcr.io/r-hub/containers/clang-asan Rscript -e ' writeLines(" #include <stdlib.h> void repr(int * foo) { int * volatile bar = NULL; int * baz = &bar[0]; if (*foo == 42) *foo = *baz; // do not give me 42 } ", "repr.c") tools::Rcmd("SHLIB repr.c") dyn.load("repr.so") .C("repr", integer(1)) ' using C compiler: ‘Ubuntu clang version 19.1.7 (++20250114103320+cd708029e0b2-1~exp1~20250114103432.75)’ clang-19 -fsanitize=address,undefined -fno-sanitize=float-divide-by-zero -fno-sanitize=alignment -fno-omit-frame-pointer -fsanitize=pointer-overflow -fsanitize-trap=pointer-overflow -fsanitize=signed-integer-overflow -I"/opt/R/devel-asan/lib/R/include" -DNDEBUG -I/usr/local/clang/include -I/usr/local/include -fpic -g -O3 -Wall -pedantic -Wp,-D_FORTIFY_SOURCE=3 -c repr.c -o repr.o clang-19 -fsanitize=address,undefined -fno-sanitize=float-divide-by-zero -fno-sanitize=alignment -fno-omit-frame-pointer -fsanitize=pointer-overflow -fsanitize-trap=pointer-overflow -fsanitize=signed-integer-overflow -shared -L/opt/R/devel-asan/lib/R/lib -L/usr/local/clang/lib -L/usr/local/lib -o repr.so repr.o -L/opt/R/devel-asan/lib/R/lib -lR *** caught illegal operation *** address 0x7feb7fb0759a, cause 'illegal operand' Traceback: 1: .C("repr", integer(1)) An irrecoverable exception occurred. R is aborting now ... ``` Here, `SIGILL` is all we've got. Why'd my workflow crash? 2. If we remove the `-fsanitize-trap` argument, the error is still caught, but now we have the diagnostics we've came to UBsan for, and the process survives: ``` $ podman run --rm -it ghcr.io/r-hub/containers/clang-asan Rscript -e ' system(r"{sed -i -e "s/-fsanitize-trap\S*//g" /opt/R/devel-asan/lib/R/etc/Makeconf}") writeLines(" #include <stdlib.h> void repr(int * foo) { int * volatile bar = NULL; int * baz = &bar[0]; if (*foo == 42) *foo = *baz; // do not give me 42 } ", "repr.c") tools::Rcmd("SHLIB repr.c") dyn.load("repr.so") .C("repr", integer(1)) ' using C compiler: ‘Ubuntu clang version 19.1.7 (++20250114103320+cd708029e0b2-1~exp1~20250114103432.75)’ clang-19 -fsanitize=address,undefined -fno-sanitize=float-divide-by-zero -fno-sanitize=alignment -fno-omit-frame-pointer -fsanitize=pointer-overflow -fsanitize=signed-integer-overflow -I"/opt/R/devel-asan/lib/R/include" -DNDEBUG -I/usr/local/clang/include -I/usr/local/include -fpic -g -O3 -Wall -pedantic -Wp,-D_FORTIFY_SOURCE=3 -c repr.c -o repr.o clang-19 -fsanitize=address,undefined -fno-sanitize=float-divide-by-zero -fno-sanitize=alignment -fno-omit-frame-pointer -fsanitize=pointer-overflow -fsanitize=signed-integer-overflow -shared -L/opt/R/devel-asan/lib/R/lib -L/usr/local/clang/lib -L/usr/local/lib -o repr.so repr.o -L/opt/R/devel-asan/lib/R/lib -lR repr.c:5:17: runtime error: applying zero offset to null pointer #0 0x7effdac565d3 in repr /repr.c:5:17 #1 0x7f006e2d9ea5 in do_dotCode /tmp/R-devel/src/main/dotcode.c:1963:2 #2 0x7f006e30ab76 in Rf_eval /tmp/R-devel/src/main/eval.c:1260:9 #3 0x7f006e35a721 in Rf_ReplIteration /tmp/R-devel/src/main/main.c:265:2 #4 0x7f006e35bc9e in R_ReplConsole /tmp/R-devel/src/main/main.c:317:11 #5 0x7f006e35bc9e in run_Rmainloop /tmp/R-devel/src/main/main.c:1219:5 #6 0x7f006e35bd0a in Rf_mainloop /tmp/R-devel/src/main/main.c:1226:5 #7 0x563b0c3fbf07 in main /tmp/R-devel/src/main/Rmain.c:29:5 #8 0x7f006dd74d8f (/usr/lib/x86_64-linux-gnu/libc.so.6+0x29d8f) (BuildId: 490fef8403240c91833978d494d39e537409b92e) #9 0x7f006dd74e3f in __libc_start_main (/usr/lib/x86_64-linux-gnu/libc.so.6+0x29e3f) (BuildId: 490fef8403240c91833978d494d39e537409b92e) #10 0x563b0c31a354 in _start (/opt/R/devel-asan/lib/R/bin/exec/R+0x2c354) (BuildId: ff82bc7c98c181240e9a80ccd227fb032965c6c4) SUMMARY: UndefinedBehaviorSanitizer: undefined-behavior repr.c:5:17 [[1]] [1] 0 ```