pub static TRACE_GROUP_END: Lazy<bool>Expand description
Cached snapshot of LXML_TRACE_GROUP_END env var, sampled exactly
once per process. Inlining std::env::var(...) on the hot
read_x_token path was triggering SIGSEGVs in __GI_getenv under
concurrent test-thread execution: glibc’s getenv walks the
process-global environ array unprotected, and the volume of
concurrent calls (millions/sec across N threads) made the unsafe
concurrent walks visible. The fix is to read the env var ONCE at
static-init time; subsequent checks are a free atomic load.