some CurrentSpan cleanup

[rust.git] / README.md

diff --git a/README.md b/README.md
index d1dde153c47870457fbd5cc9b015ce1c2bbf3d29..c7a3200dbd90439c7fa7534941b415fd79f941df 100644 (file)
--- a/README.md
+++ b/README.md
@@ -282,9 +282,8 @@ environment variable. We first document the most relevant and most commonly used
   verbose. `hide` hides the warning entirely.
 * `-Zmiri-env-exclude=<var>` keeps the `var` environment variable isolated from the host so that it
   cannot be accessed by the program. Can be used multiple times to exclude several variables. The
-  `TERM` environment variable is excluded by default to [speed up the test
-  harness](https://github.com/rust-lang/miri/issues/1702). This has no effect unless
-  `-Zmiri-disable-isolation` is also set.
+  `TERM` environment variable is excluded by default in Windows to prevent the libtest harness from
+  accessing the file system. This has no effect unless `-Zmiri-disable-isolation` is also set.
 * `-Zmiri-env-forward=<var>` forwards the `var` environment variable to the interpreted program. Can
   be used multiple times to forward several variables. This takes precedence over
   `-Zmiri-env-exclude`: if a variable is both forwarded and exluced, it *will* get forwarded. This
@@ -377,6 +376,9 @@ to Miri failing to detect cases of undefined behavior in a program.
   happening and where in your code would be a good place to look for it.
   Specifying this argument multiple times does not overwrite the previous
   values, instead it appends its values to the list. Listing a tag multiple times has no effect.
+* `-Zmiri-track-weak-memory-loads` shows a backtrace when weak memory emulation returns an outdated
+  value from a load. This can help diagnose problems that disappear under
+  `-Zmiri-disable-weak-memory-emulation`.
 
 [function ABI]: https://doc.rust-lang.org/reference/items/functions.html#extern-function-qualifier
 
@@ -393,6 +395,9 @@ Some native rustc `-Z` flags are also very relevant for Miri:
 
 Moreover, Miri recognizes some environment variables:
 
+* `MIRI_AUTO_OPS` indicates whether the automatic execution of rustfmt, clippy and rustup-toolchain
+  should be skipped. If it is set to any value, they are skipped. This is used for avoiding
+  infinite recursion in `./miri` and to allow automated IDE actions to avoid the auto ops.
 * `MIRI_LOG`, `MIRI_BACKTRACE` control logging and backtrace printing during
   Miri executions, also [see "Testing the Miri driver" in `CONTRIBUTING.md`][testing-miri].
 * `MIRIFLAGS` (recognized by `cargo miri` and the test suite) defines extra
@@ -403,10 +408,9 @@ Moreover, Miri recognizes some environment variables:
   checkout. Note that changing files in that directory does not automatically
   trigger a re-build of the standard library; you have to clear the Miri build
   cache manually (on Linux, `rm -rf ~/.cache/miri`).
-* `MIRI_SYSROOT` (recognized by `cargo miri` and the test suite) indicates the
-  sysroot to use. Only set this if you do not want to use the automatically
-  created sysroot. (The `miri` driver sysroot is controlled via the `--sysroot`
-  flag instead.)
+* `MIRI_SYSROOT` (recognized by `cargo miri` and the Miri driver) indicates the sysroot to use. When
+  using `cargo miri`, only set this if you do not want to use the automatically created sysroot. For
+  directly invoking the Miri driver, this variable (or a `--sysroot` flag) is mandatory.
 * `MIRI_TEST_TARGET` (recognized by the test suite and the `./miri` script) indicates which target
   architecture to test against.  `miri` and `cargo miri` accept the `--target` flag for the same
   purpose.
@@ -442,6 +446,8 @@ binaries, and as such worth documenting:
   crate currently being compiled.
 * `MIRI_VERBOSE` when set to any value tells the various `cargo-miri` phases to
   perform verbose logging.
+* `MIRI_HOST_SYSROOT` is set by bootstrap to tell `cargo-miri` which sysroot to use for *host*
+  operations.
 
 [testing-miri]: CONTRIBUTING.md#testing-the-miri-driver