From 31efdaa8c7045dfb218dcfea4d8f2d5b4193a967 Mon Sep 17 00:00:00 2001
From: Yuriy Glukhov <yglukhov@users.noreply.github.com>
Date: Tue, 13 Nov 2018 14:15:28 +0200
Subject: [PATCH] Update README.md

---
 README.md | 22 +++++++++++++++++++++-
 1 file changed, 21 insertions(+), 1 deletion(-)

diff --git a/README.md b/README.md
index c457bcf..6063f45 100644
--- a/README.md
+++ b/README.md
@@ -4,7 +4,8 @@ Disclaimer: WIP
 
 This is a sample of how building eWASM contracts in Nim is possible.
 Requirements:
-* clang 6.0 or later with WebAssembly support. Most likely has to be built manually.
+* clang 7.0 or later with WebAssembly support. Most likely has to be built manually.
+* 32bit version of libc. On linuxes it is usually provided by the package manager.
 * `wasm2wat` and `wat2wasm` from [wabt (WebAssembly binary toolkit)](https://github.com/WebAssembly/wabt)
 * [optional] [wasm-gc](https://github.com/alexcrichton/wasm-gc) optimizer
 
@@ -14,6 +15,25 @@ export WASM_LLVM_BIN=/path/to/llvm/bin/folder
 nimble examples
 ```
 
+## Troubleshooting
+* **Emscripten doesn't work!** It is not expected to. Use clang with wasm target enabled.
+* **clang is difficult to build.** No, it's easy. Follow these steps:
+```
+tag=release_70
+INSTALL_PREFIX=$(pwd)/llvm-wasm
+git clone --depth 1 --branch $tag https://github.com/llvm-mirror/llvm.git
+cd llvm/tools
+git clone --depth 1 --branch $tag https://github.com/llvm-mirror/clang
+git clone --depth 1 --branch $tag https://github.com/llvm-mirror/lld
+cd ..
+mkdir build
+cd build
+cmake -G "Unix Makefiles" -DCMAKE_BUILD_TYPE=Release -DCMAKE_INSTALL_PREFIX=$INSTALL_PREFIX -DLLVM_TARGETS_TO_BUILD= -DLLVM_EXPERIMENTAL_TARGETS_TO_BUILD=WebAssembly ..
+make -j 4 install
+```
+* **C compiler errors: headers not found.** Make sure you have 32bit libc installed and visible to your clang.
+
+
 ## License
 
 Licensed under one of the following: