don't forcefully enable debug assertions, but make -debug mode usable

still set those flags on CI though, we want to catch overflow there

Cargo.toml

@@ -57,3 +57,6 @@ default = ["stack-cache"]
 # Will be enabled on CI via `--all-features`.
 expensive-debug-assertions = []
 stack-cache = []
+
+[profile.dev]
+opt-level = 2 # because it's too slow otherwise

ci.sh

@@ -3,7 +3,7 @@ set -euo pipefail
 set -x
 
 # Determine configuration
-export RUSTFLAGS="-D warnings"
+export RUSTFLAGS="-D warnings -C debug-assertions -C debuginfo=1"
 export CARGO_INCREMENTAL=0
 export CARGO_EXTRA_FLAGS="--all-features" # in particular, expensive-debug-assertions
 

miri

@@ -108,9 +108,7 @@ if [ -z "$CARGO_TARGET_DIR" ]; then
     export CARGO_TARGET_DIR="$MIRIDIR/target"
 fi
 # We set the rpath so that Miri finds the private rustc libraries it needs.
-# We enable debug-assertions to get tracing.
-# We enable line-only debuginfo for backtraces.
-export RUSTFLAGS="-C link-args=-Wl,-rpath,$LIBDIR -C debug-assertions -C debuginfo=1 $RUSTFLAGS"
+export RUSTFLAGS="-C link-args=-Wl,-rpath,$LIBDIR $RUSTFLAGS"
 # Determine flags passed to all cargo invocations.
 # This is a bit more annoying that one would hope due to
 # <https://github.com/rust-lang/cargo/issues/6992>.