Trigger ICE on nightly if validators disagree

[rust.git] / README.md

diff --git a/README.md b/README.md
index 724bc36ecc6fb7fd2bb6b9783416528c7554b9ae..96d7e938be2f2ca8cbf253e70213530827a547c4 100644 (file)
--- a/README.md
+++ b/README.md
@@ -26,12 +26,13 @@ or reading the [rustc guide][rustcguidebuild].
 ### Building on *nix
 1. Make sure you have installed the dependencies:
 
-   * `g++` 4.7 or later or `clang++` 3.x or later
+   * `g++` 5.1 or later or `clang++` 3.5 or later
    * `python` 2.7 (but not 3.x)
    * GNU `make` 3.81 or later
    * `cmake` 3.4.3 or later
    * `curl`
    * `git`
+   * `ssl` which comes in `libssl-dev` or `openssl-devel`
 
 2. Clone the [source] with `git`:
 
@@ -56,6 +57,8 @@ or reading the [rustc guide][rustcguidebuild].
     an installation (using `./x.py install`) that you set the `prefix` value
     in the `[install]` section to a directory that you have write permissions.
 
+    Create install directory if you are not installing in default directory
+
 4. Build and install:
 
     ```sh
@@ -148,6 +151,17 @@ by manually calling the appropriate vcvars file before running the bootstrap.
 > python x.py build
 ```
 
+### Building rustc with older host toolchains
+It is still possible to build Rust with the older toolchain versions listed below, but only if the
+LLVM_TEMPORARILY_ALLOW_OLD_TOOLCHAIN option is set to true in the config.toml file.
+
+* Clang 3.1
+* Apple Clang 3.1
+* GCC 4.8
+* Visual Studio 2015 (Update 3)
+
+Toolchain versions older than what is listed above cannot be used to build rustc.
+
 #### Specifying an ABI
 
 Each specific ABI can also be used from either environment (for example, using