From 880b041f3cfc03443d4b4723f0b0cba565ee6177 Mon Sep 17 00:00:00 2001
From: JonathanS <mail@strfry.org>
Date: Wed, 17 Oct 2018 22:13:21 +0200
Subject: [PATCH 01/13] Enable dist-x86_64-musl as a host architexture

---
 src/ci/docker/dist-x86_64-musl/Dockerfile | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/src/ci/docker/dist-x86_64-musl/Dockerfile b/src/ci/docker/dist-x86_64-musl/Dockerfile
index 06f8a2fbba836..e6ffac4019946 100644
--- a/src/ci/docker/dist-x86_64-musl/Dockerfile
+++ b/src/ci/docker/dist-x86_64-musl/Dockerfile
@@ -41,6 +41,8 @@ ENV RUST_CONFIGURE_ARGS \
 # See: https://github.com/rust-lang/rust/issues/34978
 ENV CFLAGS_x86_64_unknown_linux_musl=-Wa,-mrelax-relocations=no
 
+ENV HOSTS=x86_64-unknown-linux-musl
+
 ENV SCRIPT \
-      python2.7 ../x.py test --target x86_64-unknown-linux-musl && \
-      python2.7 ../x.py dist --target x86_64-unknown-linux-musl
+      python2.7 ../x.py test --host $HOSTS --target $HOSTS && \
+      python2.7 ../x.py dist --host $HOSTS --target $HOSTS

From 3729e48bf2c6bc45b3efdee56ec2ce2cbcffe900 Mon Sep 17 00:00:00 2001
From: Jonathan Sieber <mail@strfry.org>
Date: Thu, 18 Oct 2018 21:47:26 +0200
Subject: [PATCH 02/13] Set RUSTFLAGS env to make dylib work

The musl-target doesn't automatically disable static linking of musl when building a dylib, and then complains it can't build a dylib.
As a workaround, disable static linking via RUSTFLAGS, to see how far the build gets.
The proper fix is to have rustc figure that out automagically.
---
 src/ci/docker/dist-x86_64-musl/Dockerfile | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/src/ci/docker/dist-x86_64-musl/Dockerfile b/src/ci/docker/dist-x86_64-musl/Dockerfile
index e6ffac4019946..441c2e7c57a07 100644
--- a/src/ci/docker/dist-x86_64-musl/Dockerfile
+++ b/src/ci/docker/dist-x86_64-musl/Dockerfile
@@ -43,6 +43,8 @@ ENV CFLAGS_x86_64_unknown_linux_musl=-Wa,-mrelax-relocations=no
 
 ENV HOSTS=x86_64-unknown-linux-musl
 
+ENV RUSTFLAGS="-C target-feature=-crt-static"
+
 ENV SCRIPT \
       python2.7 ../x.py test --host $HOSTS --target $HOSTS && \
       python2.7 ../x.py dist --host $HOSTS --target $HOSTS

From aecb32ce6e80862562a728a6bee7b741b299d988 Mon Sep 17 00:00:00 2001
From: Jonathan Sieber <mail@strfry.org>
Date: Fri, 19 Oct 2018 19:04:33 +0000
Subject: [PATCH 03/13] build a proper c++-enabled musl toolchain with
 musl-cross-make

---
 src/ci/docker/dist-x86_64-musl/Dockerfile | 22 ++++----
 src/ci/docker/scripts/musl-toolchain.sh   | 66 +++++++++++++++++++++++
 2 files changed, 79 insertions(+), 9 deletions(-)
 create mode 100644 src/ci/docker/scripts/musl-toolchain.sh

diff --git a/src/ci/docker/dist-x86_64-musl/Dockerfile b/src/ci/docker/dist-x86_64-musl/Dockerfile
index 441c2e7c57a07..2f538a28b4364 100644
--- a/src/ci/docker/dist-x86_64-musl/Dockerfile
+++ b/src/ci/docker/dist-x86_64-musl/Dockerfile
@@ -4,6 +4,7 @@ RUN apt-get update && apt-get install -y --no-install-recommends \
   g++ \
   make \
   file \
+  wget \
   curl \
   ca-certificates \
   python2.7 \
@@ -18,19 +19,17 @@ RUN apt-get update && apt-get install -y --no-install-recommends \
 
 WORKDIR /build/
 
-COPY scripts/musl.sh /build/
+COPY scripts/musl-toolchain.sh /build/
 # We need to mitigate rust-lang/rust#34978 when compiling musl itself as well
-RUN CC=gcc \
-    CFLAGS="-Wa,-mrelax-relocations=no" \
-    CXX=g++ \
-    CXXFLAGS="-Wa,-mrelax-relocations=no" \
-    bash musl.sh x86_64 && rm -rf /build
+# TODO: Check what this issue is and if we can ignore it
+
+RUN bash musl-toolchain.sh x86_64-linux-musl && rm -rf build
 
 COPY scripts/sccache.sh /scripts/
 RUN sh /scripts/sccache.sh
 
 ENV RUST_CONFIGURE_ARGS \
-      --musl-root-x86_64=/musl-x86_64 \
+      --musl-root-x86_64=/usr/local/x86_64-linux-musl \
       --enable-extended \
       --disable-docs
 
@@ -39,9 +38,14 @@ ENV RUST_CONFIGURE_ARGS \
 # way to produce "super compatible" binaries.
 #
 # See: https://github.com/rust-lang/rust/issues/34978
-ENV CFLAGS_x86_64_unknown_linux_musl=-Wa,-mrelax-relocations=no
+#ENV CFLAGS_x86_64_unknown_linux_musl=-Wa,-mrelax-relocations=no
+
+ENV HOSTS=x86_64-unknown-linux-musl \
+    CC_x86_64_unknown_linux_musl=x86_64-linux-musl-gcc \
+    CXX_x86_64_unknown_linux_musl=x86_64-linux-musl-g++
 
-ENV HOSTS=x86_64-unknown-linux-musl
+#    CARGO_TARGET_ARM_UNKNOWN_LINUX_MUSLEABIHF_LINKER=musl-gcc \
+#    CARGO_TARGET_ARM_UNKNOWN_LINUX_MUSLEABIHF_RUNNER="qemu-arm -L /musl-arm"
 
 ENV RUSTFLAGS="-C target-feature=-crt-static"
 
diff --git a/src/ci/docker/scripts/musl-toolchain.sh b/src/ci/docker/scripts/musl-toolchain.sh
new file mode 100644
index 0000000000000..db609a8666f30
--- /dev/null
+++ b/src/ci/docker/scripts/musl-toolchain.sh
@@ -0,0 +1,66 @@
+# Copyright 2016 The Rust Project Developers. See the COPYRIGHT
+# file at the top-level directory of this distribution and at
+# http://rust-lang.org/COPYRIGHT.
+#
+# Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+# http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+# <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+# option. This file may not be copied, modified, or distributed
+# except according to those terms.
+
+set -ex
+
+hide_output() {
+  set +x
+  on_err="
+echo ERROR: An error was encountered with the build.
+cat /tmp/build.log
+exit 1
+"
+  trap "$on_err" ERR
+  bash -c "while true; do sleep 30; echo \$(date) - building ...; done" &
+  PING_LOOP_PID=$!
+  $@ &> /tmp/build.log
+  trap - ERR
+  kill $PING_LOOP_PID
+  rm /tmp/build.log
+  set -x
+}
+
+TARGET=$1
+OUTPUT=/usr/local
+shift
+
+git clone https://github.com/richfelker/musl-cross-make -b v0.9.7
+cd musl-cross-make
+
+hide_output make -j$(nproc) TARGET=$TARGET
+hide_output make install TARGET=$TARGET OUTPUT=$OUTPUT
+
+cd ..
+
+export CC=$TARGET-gcc
+export CXX=$TARGET-g++
+
+LLVM=60
+
+# may have been downloaded in a previous run
+if [ ! -d libunwind-release_$LLVM ]; then
+  curl -L https://github.com/llvm-mirror/llvm/archive/release_$LLVM.tar.gz | tar xzf -
+  curl -L https://github.com/llvm-mirror/libunwind/archive/release_$LLVM.tar.gz | tar xzf -
+fi
+
+mkdir libunwind-build
+cd libunwind-build
+cmake ../libunwind-release_$LLVM \
+          -DLLVM_PATH=/build/llvm-release_$LLVM \
+          -DLIBUNWIND_ENABLE_SHARED=0 \
+          -DCMAKE_C_COMPILER=$CC \
+          -DCMAKE_CXX_COMPILER=$CXX \
+          -DCMAKE_C_FLAGS="$CFLAGS" \
+          -DCMAKE_CXX_FLAGS="$CXXFLAGS"
+
+hide_output make -j$(nproc)
+cp lib/libunwind.a $OUTPUT/$TARGET/lib
+cd ../ && rm -rf libunwind-build
+

From 8e2aa524ed47a8a797141ff47f6bcc5242caa270 Mon Sep 17 00:00:00 2001
From: Jonathan Sieber <mail@strfry.org>
Date: Fri, 19 Oct 2018 20:28:34 +0000
Subject: [PATCH 04/13] Make the musl dynamic loader known to the system, so it
 can execute target binaries

---
 src/ci/docker/scripts/musl-toolchain.sh | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/src/ci/docker/scripts/musl-toolchain.sh b/src/ci/docker/scripts/musl-toolchain.sh
index db609a8666f30..0406d5182e8f6 100644
--- a/src/ci/docker/scripts/musl-toolchain.sh
+++ b/src/ci/docker/scripts/musl-toolchain.sh
@@ -28,6 +28,10 @@ exit 1
 }
 
 TARGET=$1
+#ARCH=$1
+#TARGET=linux-musl-$ARCH
+ARCH=x86_64
+
 OUTPUT=/usr/local
 shift
 
@@ -39,6 +43,13 @@ hide_output make install TARGET=$TARGET OUTPUT=$OUTPUT
 
 cd ..
 
+# Make musl binaries executable
+
+ln -s $OUTPUT/$TARGET/lib/ld-musl-$ARCH.so.1 /lib
+ln -s $OUTPUT/$TARGET/lib/libc.so /lib
+echo $OUTPUT/$TARGET/lib >> /etc/ld-musl-$ARCH.path
+
+
 export CC=$TARGET-gcc
 export CXX=$TARGET-g++
 

From 3f107fd43a32b76da558855a5793bc922ef1fac8 Mon Sep 17 00:00:00 2001
From: Jonathan Sieber <mail@strfry.org>
Date: Tue, 27 Nov 2018 20:56:34 +0100
Subject: [PATCH 05/13] musl-toolchain: fix global lib paths (dont create
 /lib/libc.so)

---
 src/ci/docker/scripts/musl-toolchain.sh | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/src/ci/docker/scripts/musl-toolchain.sh b/src/ci/docker/scripts/musl-toolchain.sh
index 0406d5182e8f6..25781c747493a 100644
--- a/src/ci/docker/scripts/musl-toolchain.sh
+++ b/src/ci/docker/scripts/musl-toolchain.sh
@@ -45,8 +45,7 @@ cd ..
 
 # Make musl binaries executable
 
-ln -s $OUTPUT/$TARGET/lib/ld-musl-$ARCH.so.1 /lib
-ln -s $OUTPUT/$TARGET/lib/libc.so /lib
+ln -s $OUTPUT/$TARGET/lib/libc.so /lib/ld-musl-$ARCH.so.1
 echo $OUTPUT/$TARGET/lib >> /etc/ld-musl-$ARCH.path
 
 

From 52a3311dc9b5350536851baaa30ee6240374b5e9 Mon Sep 17 00:00:00 2001
From: Martell Malone <martellmalone@gmail.com>
Date: Sat, 5 Jan 2019 12:59:46 -0800
Subject: [PATCH 06/13] Address review comments

---
 src/ci/docker/scripts/musl-toolchain.sh | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/ci/docker/scripts/musl-toolchain.sh b/src/ci/docker/scripts/musl-toolchain.sh
index 25781c747493a..11954b82b8444 100644
--- a/src/ci/docker/scripts/musl-toolchain.sh
+++ b/src/ci/docker/scripts/musl-toolchain.sh
@@ -41,7 +41,7 @@ cd musl-cross-make
 hide_output make -j$(nproc) TARGET=$TARGET
 hide_output make install TARGET=$TARGET OUTPUT=$OUTPUT
 
-cd ..
+cd -
 
 # Make musl binaries executable
 
@@ -72,5 +72,5 @@ cmake ../libunwind-release_$LLVM \
 
 hide_output make -j$(nproc)
 cp lib/libunwind.a $OUTPUT/$TARGET/lib
-cd ../ && rm -rf libunwind-build
+cd - && rm -rf libunwind-build
 

From cacb3053e86f7c3f6eb60e6e25f8bb888d809ba3 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Mateusz=20Miku=C5=82a?= <matti@marinelayer.io>
Date: Fri, 11 Jan 2019 18:45:37 +0100
Subject: [PATCH 07/13] musl: update LLVM to 7

---
 src/ci/docker/scripts/musl-toolchain.sh | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/ci/docker/scripts/musl-toolchain.sh b/src/ci/docker/scripts/musl-toolchain.sh
index 11954b82b8444..45bca4bfdfe48 100644
--- a/src/ci/docker/scripts/musl-toolchain.sh
+++ b/src/ci/docker/scripts/musl-toolchain.sh
@@ -52,7 +52,7 @@ echo $OUTPUT/$TARGET/lib >> /etc/ld-musl-$ARCH.path
 export CC=$TARGET-gcc
 export CXX=$TARGET-g++
 
-LLVM=60
+LLVM=70
 
 # may have been downloaded in a previous run
 if [ ! -d libunwind-release_$LLVM ]; then

From cbc1ce0b840830a7a390716bc8be435457892436 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Mateusz=20Miku=C5=82a?= <matti@marinelayer.io>
Date: Sat, 10 Feb 2018 14:03:13 +0100
Subject: [PATCH 08/13] Drop copyright notice from musl-toolchain

---
 src/ci/docker/scripts/musl-toolchain.sh | 10 ----------
 1 file changed, 10 deletions(-)

diff --git a/src/ci/docker/scripts/musl-toolchain.sh b/src/ci/docker/scripts/musl-toolchain.sh
index 45bca4bfdfe48..00b6a113da105 100644
--- a/src/ci/docker/scripts/musl-toolchain.sh
+++ b/src/ci/docker/scripts/musl-toolchain.sh
@@ -1,13 +1,3 @@
-# Copyright 2016 The Rust Project Developers. See the COPYRIGHT
-# file at the top-level directory of this distribution and at
-# http://rust-lang.org/COPYRIGHT.
-#
-# Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
-# http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
-# <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
-# option. This file may not be copied, modified, or distributed
-# except according to those terms.
-
 set -ex
 
 hide_output() {

From 4dd57efae294a13a132b97325e7e89bc763e85e0 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Mateusz=20Miku=C5=82a?= <matti@marinelayer.io>
Date: Mon, 4 Mar 2019 14:00:05 +0100
Subject: [PATCH 09/13] Disable relax relocations again

---
 src/ci/docker/dist-x86_64-musl/Dockerfile | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/src/ci/docker/dist-x86_64-musl/Dockerfile b/src/ci/docker/dist-x86_64-musl/Dockerfile
index 2f538a28b4364..3a95bfd6ef485 100644
--- a/src/ci/docker/dist-x86_64-musl/Dockerfile
+++ b/src/ci/docker/dist-x86_64-musl/Dockerfile
@@ -22,8 +22,9 @@ WORKDIR /build/
 COPY scripts/musl-toolchain.sh /build/
 # We need to mitigate rust-lang/rust#34978 when compiling musl itself as well
 # TODO: Check what this issue is and if we can ignore it
-
-RUN bash musl-toolchain.sh x86_64-linux-musl && rm -rf build
+RUN CFLAGS="-Wa,-mrelax-relocations=no" \
+    CXXFLAGS="-Wa,-mrelax-relocations=no" \
+    bash musl-toolchain.sh x86_64-linux-musl && rm -rf build
 
 COPY scripts/sccache.sh /scripts/
 RUN sh /scripts/sccache.sh
@@ -38,7 +39,7 @@ ENV RUST_CONFIGURE_ARGS \
 # way to produce "super compatible" binaries.
 #
 # See: https://github.com/rust-lang/rust/issues/34978
-#ENV CFLAGS_x86_64_unknown_linux_musl=-Wa,-mrelax-relocations=no
+ENV CFLAGS_x86_64_unknown_linux_musl=-Wa,-mrelax-relocations=no
 
 ENV HOSTS=x86_64-unknown-linux-musl \
     CC_x86_64_unknown_linux_musl=x86_64-linux-musl-gcc \

From 66de5c6e90ff3975bcef01de90bac82a8e92fc8f Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Mateusz=20Miku=C5=82a?= <matti@marinelayer.io>
Date: Tue, 12 Mar 2019 17:15:03 +0100
Subject: [PATCH 10/13] Move testing to test-various

---
 src/ci/docker/dist-x86_64-musl/Dockerfile |  4 +---
 src/ci/docker/test-various/Dockerfile     | 20 ++++++++++++++++++--
 2 files changed, 19 insertions(+), 5 deletions(-)

diff --git a/src/ci/docker/dist-x86_64-musl/Dockerfile b/src/ci/docker/dist-x86_64-musl/Dockerfile
index 3a95bfd6ef485..543b9377357fa 100644
--- a/src/ci/docker/dist-x86_64-musl/Dockerfile
+++ b/src/ci/docker/dist-x86_64-musl/Dockerfile
@@ -50,6 +50,4 @@ ENV HOSTS=x86_64-unknown-linux-musl \
 
 ENV RUSTFLAGS="-C target-feature=-crt-static"
 
-ENV SCRIPT \
-      python2.7 ../x.py test --host $HOSTS --target $HOSTS && \
-      python2.7 ../x.py dist --host $HOSTS --target $HOSTS
+ENV SCRIPT python2.7 ../x.py dist --host $HOSTS --target $HOSTS
diff --git a/src/ci/docker/test-various/Dockerfile b/src/ci/docker/test-various/Dockerfile
index 6c419e13c9f05..f70ea9da92e73 100644
--- a/src/ci/docker/test-various/Dockerfile
+++ b/src/ci/docker/test-various/Dockerfile
@@ -11,7 +11,10 @@ RUN apt-get update && apt-get install -y --no-install-recommends \
   cmake \
   sudo \
   gdb \
-  xz-utils
+  xz-utils \
+  # for musl
+  wget \
+  patch
 
 # FIXME: build the `ptx-linker` instead.
 RUN curl -sL https://github.com/denzp/rust-ptx-linker/releases/download/v0.9.0-alpha.2/rust-ptx-linker.linux64.tar.gz | \
@@ -20,10 +23,18 @@ RUN curl -sL https://github.com/denzp/rust-ptx-linker/releases/download/v0.9.0-a
 RUN curl -sL https://nodejs.org/dist/v9.2.0/node-v9.2.0-linux-x64.tar.xz | \
   tar -xJ
 
+WORKDIR /build/
+COPY scripts/musl-toolchain.sh /build/
+RUN CFLAGS="-Wa,-mrelax-relocations=no" \
+    CXXFLAGS="-Wa,-mrelax-relocations=no" \
+    bash musl-toolchain.sh x86_64-linux-musl && rm -rf build
+WORKDIR /
+
 COPY scripts/sccache.sh /scripts/
 RUN sh /scripts/sccache.sh
 
 ENV RUST_CONFIGURE_ARGS \
+  --musl-root-x86_64=/usr/local/x86_64-linux-musl \
   --set build.nodejs=/node-v9.2.0-linux-x64/bin/node \
   --set rust.lld
 
@@ -47,4 +58,9 @@ ENV NVPTX_TARGETS=nvptx64-nvidia-cuda
 ENV NVPTX_SCRIPT python2.7 /checkout/x.py test --target $NVPTX_TARGETS \
   src/test/run-make
 
-ENV SCRIPT $WASM_SCRIPT && $NVPTX_SCRIPT
+ENV MUSL_TARGETS=x86_64-unknown-linux-musl \
+    CC_x86_64_unknown_linux_musl=x86_64-linux-musl-gcc \
+    CXX_x86_64_unknown_linux_musl=x86_64-linux-musl-g++
+ENV MUSL_SCRIPT python2.7 /checkout/x.py test --target $MUSL_TARGETS
+
+ENV SCRIPT $WASM_SCRIPT && $NVPTX_SCRIPT && $MUSL_SCRIPT

From 17464a7b877c83cb506ccac33347a6c777b78159 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Mateusz=20Miku=C5=82a?= <matti@marinelayer.io>
Date: Wed, 13 Mar 2019 22:18:13 +0100
Subject: [PATCH 11/13] Final cleanups

---
 src/ci/docker/dist-x86_64-musl/Dockerfile |  8 +++-----
 src/ci/docker/scripts/musl-toolchain.sh   | 10 ++++------
 src/ci/docker/test-various/Dockerfile     |  2 +-
 3 files changed, 8 insertions(+), 12 deletions(-)

diff --git a/src/ci/docker/dist-x86_64-musl/Dockerfile b/src/ci/docker/dist-x86_64-musl/Dockerfile
index 543b9377357fa..560df2f3a5700 100644
--- a/src/ci/docker/dist-x86_64-musl/Dockerfile
+++ b/src/ci/docker/dist-x86_64-musl/Dockerfile
@@ -21,10 +21,9 @@ WORKDIR /build/
 
 COPY scripts/musl-toolchain.sh /build/
 # We need to mitigate rust-lang/rust#34978 when compiling musl itself as well
-# TODO: Check what this issue is and if we can ignore it
 RUN CFLAGS="-Wa,-mrelax-relocations=no" \
     CXXFLAGS="-Wa,-mrelax-relocations=no" \
-    bash musl-toolchain.sh x86_64-linux-musl && rm -rf build
+    bash musl-toolchain.sh x86_64 && rm -rf build
 
 COPY scripts/sccache.sh /scripts/
 RUN sh /scripts/sccache.sh
@@ -45,9 +44,8 @@ ENV HOSTS=x86_64-unknown-linux-musl \
     CC_x86_64_unknown_linux_musl=x86_64-linux-musl-gcc \
     CXX_x86_64_unknown_linux_musl=x86_64-linux-musl-g++
 
-#    CARGO_TARGET_ARM_UNKNOWN_LINUX_MUSLEABIHF_LINKER=musl-gcc \
-#    CARGO_TARGET_ARM_UNKNOWN_LINUX_MUSLEABIHF_RUNNER="qemu-arm -L /musl-arm"
-
+# Musl defaults to static libs but we need them to be dynamic for host toolchain.
+# The toolchain will produce static libs by default.
 ENV RUSTFLAGS="-C target-feature=-crt-static"
 
 ENV SCRIPT python2.7 ../x.py dist --host $HOSTS --target $HOSTS
diff --git a/src/ci/docker/scripts/musl-toolchain.sh b/src/ci/docker/scripts/musl-toolchain.sh
index 00b6a113da105..7802e15f18840 100644
--- a/src/ci/docker/scripts/musl-toolchain.sh
+++ b/src/ci/docker/scripts/musl-toolchain.sh
@@ -17,10 +17,8 @@ exit 1
   set -x
 }
 
-TARGET=$1
-#ARCH=$1
-#TARGET=linux-musl-$ARCH
-ARCH=x86_64
+ARCH=$1
+TARGET=linux-musl-$ARCH
 
 OUTPUT=/usr/local
 shift
@@ -33,8 +31,7 @@ hide_output make install TARGET=$TARGET OUTPUT=$OUTPUT
 
 cd -
 
-# Make musl binaries executable
-
+# Install musl library to make binaries executable
 ln -s $OUTPUT/$TARGET/lib/libc.so /lib/ld-musl-$ARCH.so.1
 echo $OUTPUT/$TARGET/lib >> /etc/ld-musl-$ARCH.path
 
@@ -50,6 +47,7 @@ if [ ! -d libunwind-release_$LLVM ]; then
   curl -L https://github.com/llvm-mirror/libunwind/archive/release_$LLVM.tar.gz | tar xzf -
 fi
 
+# fixme(mati865): Replace it with https://github.com/rust-lang/rust/pull/59089
 mkdir libunwind-build
 cd libunwind-build
 cmake ../libunwind-release_$LLVM \
diff --git a/src/ci/docker/test-various/Dockerfile b/src/ci/docker/test-various/Dockerfile
index f70ea9da92e73..80c6ed68cb547 100644
--- a/src/ci/docker/test-various/Dockerfile
+++ b/src/ci/docker/test-various/Dockerfile
@@ -27,7 +27,7 @@ WORKDIR /build/
 COPY scripts/musl-toolchain.sh /build/
 RUN CFLAGS="-Wa,-mrelax-relocations=no" \
     CXXFLAGS="-Wa,-mrelax-relocations=no" \
-    bash musl-toolchain.sh x86_64-linux-musl && rm -rf build
+    bash musl-toolchain.sh x86_64 && rm -rf build
 WORKDIR /
 
 COPY scripts/sccache.sh /scripts/

From f364f483a3d79248b2b6b576097e27ffdacfe38e Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Mateusz=20Miku=C5=82a?= <matti@marinelayer.io>
Date: Thu, 14 Mar 2019 16:55:47 +0100
Subject: [PATCH 12/13] Address final review

---
 src/ci/docker/scripts/musl-toolchain.sh | 6 ++++++
 src/ci/docker/test-various/Dockerfile   | 5 +----
 2 files changed, 7 insertions(+), 4 deletions(-)

diff --git a/src/ci/docker/scripts/musl-toolchain.sh b/src/ci/docker/scripts/musl-toolchain.sh
index 7802e15f18840..e168760f44971 100644
--- a/src/ci/docker/scripts/musl-toolchain.sh
+++ b/src/ci/docker/scripts/musl-toolchain.sh
@@ -1,3 +1,9 @@
+# This script runs `musl-cross-make` to prepare C toolchain (Binutils, GCC, musl itself)
+# and builds static libunwind that we distribute for static target.
+#
+# Versions of the toolchain components are configurable in `musl-cross-make/Makefile` and
+# musl unlike GLIBC is forward compatible so upgrading it shouldn't break old distributions.
+# Right now we have: Binutils 2.27, GCC 6.3.0, musl 1.1.18
 set -ex
 
 hide_output() {
diff --git a/src/ci/docker/test-various/Dockerfile b/src/ci/docker/test-various/Dockerfile
index 80c6ed68cb547..60b431ad38641 100644
--- a/src/ci/docker/test-various/Dockerfile
+++ b/src/ci/docker/test-various/Dockerfile
@@ -12,7 +12,6 @@ RUN apt-get update && apt-get install -y --no-install-recommends \
   sudo \
   gdb \
   xz-utils \
-  # for musl
   wget \
   patch
 
@@ -25,9 +24,7 @@ RUN curl -sL https://nodejs.org/dist/v9.2.0/node-v9.2.0-linux-x64.tar.xz | \
 
 WORKDIR /build/
 COPY scripts/musl-toolchain.sh /build/
-RUN CFLAGS="-Wa,-mrelax-relocations=no" \
-    CXXFLAGS="-Wa,-mrelax-relocations=no" \
-    bash musl-toolchain.sh x86_64 && rm -rf build
+RUN bash musl-toolchain.sh x86_64 && rm -rf build
 WORKDIR /
 
 COPY scripts/sccache.sh /scripts/

From 451343e0f3d90904bdc2080cc8bc4eb00be0364e Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Mateusz=20Miku=C5=82a?= <mati865@users.noreply.github.com>
Date: Fri, 15 Mar 2019 01:19:54 +0100
Subject: [PATCH 13/13] Fix TARGET variable in musl-toolchain.sh

---
 src/ci/docker/scripts/musl-toolchain.sh | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/ci/docker/scripts/musl-toolchain.sh b/src/ci/docker/scripts/musl-toolchain.sh
index e168760f44971..95b7c2869c91f 100644
--- a/src/ci/docker/scripts/musl-toolchain.sh
+++ b/src/ci/docker/scripts/musl-toolchain.sh
@@ -24,7 +24,7 @@ exit 1
 }
 
 ARCH=$1
-TARGET=linux-musl-$ARCH
+TARGET=$ARCH-linux-musl
 
 OUTPUT=/usr/local
 shift