From a62a8ab20525c52de2bf37bb9125281cf5534301 Mon Sep 17 00:00:00 2001
From: Brian Carroll <brian.carroll.ireland@gmail.com>
Date: Mon, 9 May 2022 20:55:21 +0100
Subject: [PATCH 01/16] Build web REPL on Netlify

---
 www/build.sh | 22 ++++++----------------
 1 file changed, 6 insertions(+), 16 deletions(-)

diff --git a/www/build.sh b/www/build.sh
index d31c99bb64..f5a9ea868b 100755
--- a/www/build.sh
+++ b/www/build.sh
@@ -11,21 +11,9 @@ cd $SCRIPT_RELATIVE_DIR
 rm -rf build/
 cp -r public/ build/
 
-pushd build
-
 # grab the source code and copy it to Netlify's server; if it's not there, fail the build.
+pushd build
 wget https://github.com/rtfeldman/elm-css/files/8037422/roc-source-code.zip
-
-# Copy REPL webpage source files
-cp -r ../../repl_www/public/* .
-
-# grab the pre-compiled REPL and copy it to Netlify's server; if it's not there, fail the build.
-wget https://github.com/brian-carroll/mock-repl/archive/refs/heads/deploy.zip
-unzip deploy.zip
-mv mock-repl-deploy/* .
-rmdir mock-repl-deploy
-rm deploy.zip
-
 popd
 
 pushd ..
@@ -47,10 +35,12 @@ export ROC_DOCS_URL_ROOT=/builtins
 BUILTINS_WASM32_O=""
 BUILTINS_HOST_O=""
 
-# We run the CLI with --no-default-features because that way we don't have the
-# "llvm" feature and therefore don't depend on LLVM being installed on the
-# system. (Netlify's build servers have Rust installed, but not LLVM.)
 cargo run --bin roc-docs compiler/builtins/roc/*.roc
 mv generated-docs/*.* www/build # move all the .js, .css, etc. files to build/
 mv generated-docs/ www/build/builtins # move all the folders to build/builtins/
+
+# Web REPL
+repl_www/build.sh
+cp -r repl_www/public/* www/build
+
 popd

From 1c56280a2c235a00a8867dac6251d75f06e85168 Mon Sep 17 00:00:00 2001
From: Brian Carroll <brian.carroll.ireland@gmail.com>
Date: Sat, 14 May 2022 09:44:28 +0100
Subject: [PATCH 02/16] Install Zig on Netlify

---
 www/netlify.sh | 14 +++++++++-----
 1 file changed, 9 insertions(+), 5 deletions(-)

diff --git a/www/netlify.sh b/www/netlify.sh
index bf388c1ea4..72b0daa6fa 100644
--- a/www/netlify.sh
+++ b/www/netlify.sh
@@ -6,11 +6,15 @@ set -euxo pipefail
 
 rustup update
 rustup default stable
+rustup target add wasm32-unknown-unknown wasm32-wasi
 
-# TODO remove this once we actually build the web repl!
-SCRIPT_DIR=$( cd -- "$( dirname -- "${BASH_SOURCE[0]}" )" &> /dev/null && pwd )
-REPL_WASM_DATA=${SCRIPT_DIR}/../repl_wasm/data/
-mkdir -p ${REPL_WASM_DATA}
-touch ${REPL_WASM_DATA}/pre_linked_binary.o
+ZIG_DIR="zig-linux-x86_64-0.9.1"
+wget https://ziglang.org/download/0.9.1/${ZIG_DIR}.tar.xz
+
+uname -a
+
+xz --decompress ${ZIG_DIR}.tar.xz
+tar xvf ${ZIG_DIR}.tar
+export PATH="${ZIG_DIR}:${PATH}"
 
 bash build.sh

From 3e7928096d7196fd0880fa87db533cde9ef1bac7 Mon Sep 17 00:00:00 2001
From: Brian Carroll <brian.carroll.ireland@gmail.com>
Date: Sat, 14 May 2022 10:09:50 +0100
Subject: [PATCH 03/16] Clean up Netlify script

---
 www/netlify.sh | 12 ++++--------
 1 file changed, 4 insertions(+), 8 deletions(-)

diff --git a/www/netlify.sh b/www/netlify.sh
index 72b0daa6fa..7de90bfe7c 100644
--- a/www/netlify.sh
+++ b/www/netlify.sh
@@ -8,13 +8,9 @@ rustup update
 rustup default stable
 rustup target add wasm32-unknown-unknown wasm32-wasi
 
-ZIG_DIR="zig-linux-x86_64-0.9.1"
-wget https://ziglang.org/download/0.9.1/${ZIG_DIR}.tar.xz
-
-uname -a
-
-xz --decompress ${ZIG_DIR}.tar.xz
-tar xvf ${ZIG_DIR}.tar
-export PATH="${ZIG_DIR}:${PATH}"
+ZIG_DIRNAME="zig-linux-x86_64-0.9.1"
+wget https://ziglang.org/download/0.9.1/${ZIG_DIRNAME}.tar.xz
+tar --extract --xz --file=${ZIG_DIRNAME}.tar.xz
+export PATH="$(pwd)/${ZIG_DIRNAME}:${PATH}"
 
 bash build.sh

From 6a91e661921ea00d6ad4604d67ac6e938f471eb6 Mon Sep 17 00:00:00 2001
From: Brian Carroll <brian.carroll.ireland@gmail.com>
Date: Sun, 15 May 2022 12:57:37 +0100
Subject: [PATCH 04/16] Delete env var NO_ZIG_INSTALLED since Zig is now
 installed on Netlify

---
 compiler/builtins/build.rs | 9 ---------
 repl_wasm/build.rs         | 9 ---------
 www/build.sh               | 6 +-----
 3 files changed, 1 insertion(+), 23 deletions(-)

diff --git a/compiler/builtins/build.rs b/compiler/builtins/build.rs
index 59503cc89a..2805784dec 100644
--- a/compiler/builtins/build.rs
+++ b/compiler/builtins/build.rs
@@ -20,15 +20,6 @@ fn zig_executable() -> String {
 fn main() {
     println!("cargo:rerun-if-changed=build.rs");
 
-    // When we build on Netlify, zig is not installed (but also not used,
-    // since all we're doing is generating docs), so we can skip the steps
-    // that require having zig installed.
-    if env::var_os("NO_ZIG_INSTALLED").is_some() {
-        // We still need to do the other things before this point, because
-        // setting the env vars is needed for other parts of the build.
-        return;
-    }
-
     // "." is relative to where "build.rs" is
     // dunce can be removed once ziglang/zig#5109 is fixed
     let build_script_dir_path = dunce::canonicalize(Path::new(".")).unwrap();
diff --git a/repl_wasm/build.rs b/repl_wasm/build.rs
index b050c20673..832a1b7c56 100644
--- a/repl_wasm/build.rs
+++ b/repl_wasm/build.rs
@@ -13,15 +13,6 @@ fn main() {
     let source_path = format!("src/{}.c", PLATFORM_FILENAME);
     println!("cargo:rerun-if-changed={}", source_path);
 
-    // When we build on Netlify, zig is not installed (but also not used,
-    // since all we're doing is generating docs), so we can skip the steps
-    // that require having zig installed.
-    if env::var_os("NO_ZIG_INSTALLED").is_some() {
-        // We still need to do the other things before this point, because
-        // setting the env vars is needed for other parts of the build.
-        return;
-    }
-
     std::fs::create_dir_all("./data").unwrap();
 
     // Zig can produce *either* an object containing relocations OR an object containing libc code
diff --git a/www/build.sh b/www/build.sh
index f5a9ea868b..382c4a7227 100755
--- a/www/build.sh
+++ b/www/build.sh
@@ -31,15 +31,11 @@ RUSTFLAGS=-Awarnings
 # is set up to serve them.
 export ROC_DOCS_URL_ROOT=/builtins
 
-# These just need to be defined so that some env! macros don't fail.
-BUILTINS_WASM32_O=""
-BUILTINS_HOST_O=""
-
 cargo run --bin roc-docs compiler/builtins/roc/*.roc
 mv generated-docs/*.* www/build # move all the .js, .css, etc. files to build/
 mv generated-docs/ www/build/builtins # move all the folders to build/builtins/
 
-# Web REPL
+echo "Building Web REPL..."
 repl_www/build.sh
 cp -r repl_www/public/* www/build
 

From 1b6c2fccef58bc3ddb05e8aa71b7d60845e42d0f Mon Sep 17 00:00:00 2001
From: Brian Carroll <brian.carroll.ireland@gmail.com>
Date: Sun, 15 May 2022 13:45:37 +0100
Subject: [PATCH 05/16] Install wasm-opt on Netlify, since wasm-pack fails to
 do so

---
 .gitignore     |  1 +
 www/build.sh   |  3 +++
 www/netlify.sh | 12 +++++++++++-
 3 files changed, 15 insertions(+), 1 deletion(-)

diff --git a/.gitignore b/.gitignore
index 87635559c0..03c01ea6aa 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,5 +1,6 @@
 target
 generated-docs
+netlify-install
 zig-cache
 .direnv
 .envrc
diff --git a/www/build.sh b/www/build.sh
index 382c4a7227..90b1d6f20e 100755
--- a/www/build.sh
+++ b/www/build.sh
@@ -39,4 +39,7 @@ echo "Building Web REPL..."
 repl_www/build.sh
 cp -r repl_www/public/* www/build
 
+echo "Asset sizes:"
+ls -lh www/build/*
+
 popd
diff --git a/www/netlify.sh b/www/netlify.sh
index 7de90bfe7c..e9dd0e5d99 100644
--- a/www/netlify.sh
+++ b/www/netlify.sh
@@ -8,9 +8,19 @@ rustup update
 rustup default stable
 rustup target add wasm32-unknown-unknown wasm32-wasi
 
+cd netlify-install
+
 ZIG_DIRNAME="zig-linux-x86_64-0.9.1"
 wget https://ziglang.org/download/0.9.1/${ZIG_DIRNAME}.tar.xz
 tar --extract --xz --file=${ZIG_DIRNAME}.tar.xz
-export PATH="$(pwd)/${ZIG_DIRNAME}:${PATH}"
 
+# Work around an issue with wasm-pack where it fails to install wasm-opt (from binaryen) on some CI systems
+# https://github.com/rustwasm/wasm-pack/issues/864
+BINARYEN_DIRNAME="binaryen-version_108-x86_64-linux"
+wget https://github.com/WebAssembly/binaryen/releases/download/version_108/${BINARYEN_DIRNAME}.tar.gz
+tar --extract --gzip --file=${BINARYEN_DIRNAME}.tar.gz
+
+cd ..
+
+export PATH="$(pwd)/netlify-install/${BINARYEN_DIRNAME}/bin:$(pwd)/netlify-install/${ZIG_DIRNAME}:${PATH}"
 bash build.sh

From 25fdeb5ca81574c89baf4122cf922a3ca7077a6c Mon Sep 17 00:00:00 2001
From: Brian Carroll <brian.carroll.ireland@gmail.com>
Date: Sun, 15 May 2022 15:47:25 +0100
Subject: [PATCH 06/16] Install wasm-opt on Earthly

---
 Earthfile | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/Earthfile b/Earthfile
index 6f9287159c..0a13a7999f 100644
--- a/Earthfile
+++ b/Earthfile
@@ -42,6 +42,9 @@ install-zig-llvm-valgrind-clippy-rustfmt:
     RUN rustup target add wasm32-unknown-unknown wasm32-wasi
     RUN apt -y install libssl-dev
     RUN OPENSSL_NO_VENDOR=1 cargo install wasm-pack
+    RUN wget https://github.com/WebAssembly/binaryen/releases/download/version_108/binaryen-version_108-x86_64-linux.tar.gz
+    RUN tar -xzf binaryen-version_108-x86_64-linux.tar.gz
+    RUN ln -s /earthbuild/binaryen-version_108-x86_64-linux/bin/wasm-opt /bin/wasm-opt
     # criterion
     RUN cargo install cargo-criterion
     # sccache
@@ -105,7 +108,7 @@ test-rust:
     # RUN echo "4" | cargo run --locked --release --features="target-x86" -- --target=x86_32 examples/benchmarks/NQueens.roc
     # RUN --mount=type=cache,target=$SCCACHE_DIR \
     #    cargo test --locked --release --features with_sound --test cli_run i386 --features="i386-cli-run" && sccache --show-stats
-    # make sure doc generation works (that is, make sure build.sh returns status code 0)
+    # make sure website deployment works (that is, make sure build.sh returns status code 0)
     RUN bash www/build.sh
 
 

From 03ae3f3c47f4b1b99635b5729ef23b29d11c4167 Mon Sep 17 00:00:00 2001
From: Brian Carroll <brian.carroll.ireland@gmail.com>
Date: Sun, 15 May 2022 15:48:43 +0100
Subject: [PATCH 07/16] Create netlify-install directory on Netlify

---
 www/netlify.sh | 1 +
 1 file changed, 1 insertion(+)

diff --git a/www/netlify.sh b/www/netlify.sh
index e9dd0e5d99..bda845f48c 100644
--- a/www/netlify.sh
+++ b/www/netlify.sh
@@ -8,6 +8,7 @@ rustup update
 rustup default stable
 rustup target add wasm32-unknown-unknown wasm32-wasi
 
+mkdir -p netlify-install
 cd netlify-install
 
 ZIG_DIRNAME="zig-linux-x86_64-0.9.1"

From da869203247b9ad8f673c3c15ea2e4b657ef1bd5 Mon Sep 17 00:00:00 2001
From: Brian Carroll <brian.carroll.ireland@gmail.com>
Date: Mon, 16 May 2022 08:18:05 +0100
Subject: [PATCH 08/16] Try installing wasm-opt via apt

---
 .gitignore     |  1 -
 Earthfile      |  5 +----
 www/netlify.sh | 11 ++---------
 3 files changed, 3 insertions(+), 14 deletions(-)

diff --git a/.gitignore b/.gitignore
index 03c01ea6aa..87635559c0 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,6 +1,5 @@
 target
 generated-docs
-netlify-install
 zig-cache
 .direnv
 .envrc
diff --git a/Earthfile b/Earthfile
index 0a13a7999f..9aaec6d614 100644
--- a/Earthfile
+++ b/Earthfile
@@ -40,11 +40,8 @@ install-zig-llvm-valgrind-clippy-rustfmt:
     RUN rustup component add rustfmt
     # wasm repl & tests
     RUN rustup target add wasm32-unknown-unknown wasm32-wasi
-    RUN apt -y install libssl-dev
+    RUN apt -y install libssl-dev binaryen
     RUN OPENSSL_NO_VENDOR=1 cargo install wasm-pack
-    RUN wget https://github.com/WebAssembly/binaryen/releases/download/version_108/binaryen-version_108-x86_64-linux.tar.gz
-    RUN tar -xzf binaryen-version_108-x86_64-linux.tar.gz
-    RUN ln -s /earthbuild/binaryen-version_108-x86_64-linux/bin/wasm-opt /bin/wasm-opt
     # criterion
     RUN cargo install cargo-criterion
     # sccache
diff --git a/www/netlify.sh b/www/netlify.sh
index bda845f48c..3e56e9c253 100644
--- a/www/netlify.sh
+++ b/www/netlify.sh
@@ -8,20 +8,13 @@ rustup update
 rustup default stable
 rustup target add wasm32-unknown-unknown wasm32-wasi
 
-mkdir -p netlify-install
-cd netlify-install
-
 ZIG_DIRNAME="zig-linux-x86_64-0.9.1"
 wget https://ziglang.org/download/0.9.1/${ZIG_DIRNAME}.tar.xz
 tar --extract --xz --file=${ZIG_DIRNAME}.tar.xz
+export PATH="$(pwd)/${ZIG_DIRNAME}:${PATH}"
 
 # Work around an issue with wasm-pack where it fails to install wasm-opt (from binaryen) on some CI systems
 # https://github.com/rustwasm/wasm-pack/issues/864
-BINARYEN_DIRNAME="binaryen-version_108-x86_64-linux"
-wget https://github.com/WebAssembly/binaryen/releases/download/version_108/${BINARYEN_DIRNAME}.tar.gz
-tar --extract --gzip --file=${BINARYEN_DIRNAME}.tar.gz
+apt -y install binaryen
 
-cd ..
-
-export PATH="$(pwd)/netlify-install/${BINARYEN_DIRNAME}/bin:$(pwd)/netlify-install/${ZIG_DIRNAME}:${PATH}"
 bash build.sh

From c62c7c0722485e09f0e5c4d8ce80c3f6b9fe8151 Mon Sep 17 00:00:00 2001
From: Brian Carroll <brian.carroll.ireland@gmail.com>
Date: Mon, 16 May 2022 08:18:47 +0100
Subject: [PATCH 09/16] Make Cargo verbose to debug a web REPL build issuex

---
 repl_www/build.sh | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/repl_www/build.sh b/repl_www/build.sh
index 9e762ddfd4..02055230d3 100755
--- a/repl_www/build.sh
+++ b/repl_www/build.sh
@@ -26,7 +26,7 @@ then
     wasm-bindgen --target web --keep-debug target/wasm32-unknown-unknown/release/roc_repl_wasm.wasm --out-dir repl_wasm/pkg/
 else
     # A `--profiling` build is optimized and has debug info, so we get stack traces for compiler `todo!()`
-    wasm-pack build --profiling --target web repl_wasm -- --features console_error_panic_hook
+    wasm-pack build --profiling --target web repl_wasm -- --features console_error_panic_hook -v
 fi
 
 cp repl_wasm/pkg/*.wasm $WWW_ROOT

From 65bbd85cc7141f4814b57831a05b9d7da90514bc Mon Sep 17 00:00:00 2001
From: Brian Carroll <brian.carroll.ireland@gmail.com>
Date: Mon, 16 May 2022 09:02:43 +0100
Subject: [PATCH 10/16] Disable wasm-opt by default and run it when needed

---
 Earthfile            |  3 ++-
 repl_wasm/Cargo.toml |  5 +++--
 repl_www/build.sh    | 20 +++++++++-----------
 www/netlify.sh       |  8 ++++++--
 4 files changed, 20 insertions(+), 16 deletions(-)

diff --git a/Earthfile b/Earthfile
index 9aaec6d614..c9272f2ca1 100644
--- a/Earthfile
+++ b/Earthfile
@@ -40,7 +40,7 @@ install-zig-llvm-valgrind-clippy-rustfmt:
     RUN rustup component add rustfmt
     # wasm repl & tests
     RUN rustup target add wasm32-unknown-unknown wasm32-wasi
-    RUN apt -y install libssl-dev binaryen
+    RUN apt -y install libssl-dev
     RUN OPENSSL_NO_VENDOR=1 cargo install wasm-pack
     # criterion
     RUN cargo install cargo-criterion
@@ -106,6 +106,7 @@ test-rust:
     # RUN --mount=type=cache,target=$SCCACHE_DIR \
     #    cargo test --locked --release --features with_sound --test cli_run i386 --features="i386-cli-run" && sccache --show-stats
     # make sure website deployment works (that is, make sure build.sh returns status code 0)
+    ENV REPL_DEBUG=1
     RUN bash www/build.sh
 
 
diff --git a/repl_wasm/Cargo.toml b/repl_wasm/Cargo.toml
index 7acb6b2e89..c46ec537fb 100644
--- a/repl_wasm/Cargo.toml
+++ b/repl_wasm/Cargo.toml
@@ -29,5 +29,6 @@ roc_types = {path = "../compiler/types"}
 [features]
 wasmer = ["futures"]
 
-[package.metadata.wasm-pack.profile.profiling]
-wasm-opt = ['-Os', '-g'] # `wasm-pack --profiling` is supposed to have debug info `-g` by default, but doesn't
+# Tell wasm-pack not to run wasm-opt automatically. We run it explicitly when we need to.
+# (Workaround for a CI install issue with wasm-pack https://github.com/rustwasm/wasm-pack/issues/864)
+wasm-opt = false
diff --git a/repl_www/build.sh b/repl_www/build.sh
index 02055230d3..99014dcbe5 100755
--- a/repl_www/build.sh
+++ b/repl_www/build.sh
@@ -18,18 +18,16 @@ fi
 WWW_ROOT="${1:-repl_www/public}"
 mkdir -p $WWW_ROOT
 
-# When debugging the REPL, use `REPL_DEBUG=1 repl_www/build.sh`
-if [ -n "${REPL_DEBUG:-}" ]
-then
-    # Leave out wasm-opt since it takes too long when debugging, and provide some debug options
-    cargo build --target wasm32-unknown-unknown -p roc_repl_wasm --release --features console_error_panic_hook
-    wasm-bindgen --target web --keep-debug target/wasm32-unknown-unknown/release/roc_repl_wasm.wasm --out-dir repl_wasm/pkg/
-else
-    # A `--profiling` build is optimized and has debug info, so we get stack traces for compiler `todo!()`
-    wasm-pack build --profiling --target web repl_wasm -- --features console_error_panic_hook -v
-fi
+# We want a release build, but with debug info (to get stack traces for Wasm backend `todo!()`)
+# This configuration is called `--profiling`
+wasm-pack build --profiling --target web repl_wasm -- --features console_error_panic_hook -v
+cp repl_wasm/pkg/roc_repl_wasm_bg.wasm $WWW_ROOT
 
-cp repl_wasm/pkg/*.wasm $WWW_ROOT
+# To disable optimizations while debugging, run `REPL_DEBUG=1 repl_www/build.sh`
+if [ "${REPL_DEBUG:-}" == "" ]
+then
+    wasm-opt -Os --debuginfo repl_wasm/pkg/roc_repl_wasm_bg.wasm -o $WWW_ROOT/roc_repl_wasm_bg.wasm
+fi
 
 # Copy the JS from wasm_bindgen, replacing its invalid `import` statement with a `var`.
 # The JS import from the invalid path 'env', seems to be generated when there are unresolved symbols.
diff --git a/www/netlify.sh b/www/netlify.sh
index 3e56e9c253..20ea56bfc0 100644
--- a/www/netlify.sh
+++ b/www/netlify.sh
@@ -11,10 +11,14 @@ rustup target add wasm32-unknown-unknown wasm32-wasi
 ZIG_DIRNAME="zig-linux-x86_64-0.9.1"
 wget https://ziglang.org/download/0.9.1/${ZIG_DIRNAME}.tar.xz
 tar --extract --xz --file=${ZIG_DIRNAME}.tar.xz
-export PATH="$(pwd)/${ZIG_DIRNAME}:${PATH}"
+PATH="$(pwd)/${ZIG_DIRNAME}:${PATH}"
 
 # Work around an issue with wasm-pack where it fails to install wasm-opt (from binaryen) on some CI systems
 # https://github.com/rustwasm/wasm-pack/issues/864
-apt -y install binaryen
+BINARYEN_DIRNAME="binaryen-version_108-x86_64-linux"
+wget https://github.com/WebAssembly/binaryen/releases/download/version_108/${BINARYEN_DIRNAME}.tar.gz
+tar --extract --gzip --file=${BINARYEN_DIRNAME}.tar.gz
+PATH="$(pwd)/${BINARYEN_DIRNAME}/bin:${PATH}"
 
+export PATH
 bash build.sh

From a80707209ff53a2b1b7dbdb1f0dea36e4bf5f405 Mon Sep 17 00:00:00 2001
From: Brian Carroll <brian.carroll.ireland@gmail.com>
Date: Mon, 16 May 2022 09:05:42 +0100
Subject: [PATCH 11/16] Fix Cargo.toml bug

---
 repl_wasm/Cargo.toml | 1 +
 1 file changed, 1 insertion(+)

diff --git a/repl_wasm/Cargo.toml b/repl_wasm/Cargo.toml
index c46ec537fb..9388ead285 100644
--- a/repl_wasm/Cargo.toml
+++ b/repl_wasm/Cargo.toml
@@ -31,4 +31,5 @@ wasmer = ["futures"]
 
 # Tell wasm-pack not to run wasm-opt automatically. We run it explicitly when we need to.
 # (Workaround for a CI install issue with wasm-pack https://github.com/rustwasm/wasm-pack/issues/864)
+[package.metadata.wasm-pack.profile.profiling]
 wasm-opt = false

From 18380b7151687664da047b32db286e3766c234c2 Mon Sep 17 00:00:00 2001
From: Brian Carroll <brian.carroll.ireland@gmail.com>
Date: Tue, 17 May 2022 08:15:13 +0100
Subject: [PATCH 12/16] Add some CI debug lines

---
 repl_www/build.sh | 11 ++++++++++-
 www/netlify.sh    |  2 ++
 2 files changed, 12 insertions(+), 1 deletion(-)

diff --git a/repl_www/build.sh b/repl_www/build.sh
index 99014dcbe5..9a1fe410bb 100755
--- a/repl_www/build.sh
+++ b/repl_www/build.sh
@@ -18,13 +18,22 @@ fi
 WWW_ROOT="${1:-repl_www/public}"
 mkdir -p $WWW_ROOT
 
+# Debugging build scripts on CI
+lsb_release -a
+cargo --version
+rustc --version
+wasm-pack --version
+which wasm-opt && wasm-opt --version
+
+echo $PATH | tr ':' '\n'
+
 # We want a release build, but with debug info (to get stack traces for Wasm backend `todo!()`)
 # This configuration is called `--profiling`
 wasm-pack build --profiling --target web repl_wasm -- --features console_error_panic_hook -v
 cp repl_wasm/pkg/roc_repl_wasm_bg.wasm $WWW_ROOT
 
 # To disable optimizations while debugging, run `REPL_DEBUG=1 repl_www/build.sh`
-if [ "${REPL_DEBUG:-}" == "" ]
+if [ "${REPL_DEBUG:-}" == "" ] && which wasm-opt
 then
     wasm-opt -Os --debuginfo repl_wasm/pkg/roc_repl_wasm_bg.wasm -o $WWW_ROOT/roc_repl_wasm_bg.wasm
 fi
diff --git a/www/netlify.sh b/www/netlify.sh
index 20ea56bfc0..d973f943e7 100644
--- a/www/netlify.sh
+++ b/www/netlify.sh
@@ -20,5 +20,7 @@ wget https://github.com/WebAssembly/binaryen/releases/download/version_108/${BIN
 tar --extract --gzip --file=${BINARYEN_DIRNAME}.tar.gz
 PATH="$(pwd)/${BINARYEN_DIRNAME}/bin:${PATH}"
 
+echo $PATH | tr ':' '\n'
+
 export PATH
 bash build.sh

From d2fb13668f48b6e69363d1359440c35bb814ddfd Mon Sep 17 00:00:00 2001
From: Brian Carroll <brian.carroll.ireland@gmail.com>
Date: Tue, 17 May 2022 08:32:53 +0100
Subject: [PATCH 13/16] show rustup for debug

---
 repl_www/build.sh | 1 +
 1 file changed, 1 insertion(+)

diff --git a/repl_www/build.sh b/repl_www/build.sh
index 9a1fe410bb..2ba1bcdd00 100755
--- a/repl_www/build.sh
+++ b/repl_www/build.sh
@@ -22,6 +22,7 @@ mkdir -p $WWW_ROOT
 lsb_release -a
 cargo --version
 rustc --version
+rustup show
 wasm-pack --version
 which wasm-opt && wasm-opt --version
 

From b54c1e2bc5849043c00e0d56363b65c10cacaf66 Mon Sep 17 00:00:00 2001
From: Brian Carroll <brian.carroll.ireland@gmail.com>
Date: Tue, 17 May 2022 08:40:29 +0100
Subject: [PATCH 14/16] Copy .js from wasm-bindgen too!

---
 repl_www/build.sh | 5 ++++-
 www/build.sh      | 3 +--
 2 files changed, 5 insertions(+), 3 deletions(-)

diff --git a/repl_www/build.sh b/repl_www/build.sh
index 2ba1bcdd00..be68a157e5 100755
--- a/repl_www/build.sh
+++ b/repl_www/build.sh
@@ -31,12 +31,15 @@ echo $PATH | tr ':' '\n'
 # We want a release build, but with debug info (to get stack traces for Wasm backend `todo!()`)
 # This configuration is called `--profiling`
 wasm-pack build --profiling --target web repl_wasm -- --features console_error_panic_hook -v
-cp repl_wasm/pkg/roc_repl_wasm_bg.wasm $WWW_ROOT
+cp -v repl_wasm/pkg/roc_repl_wasm.js $WWW_ROOT
 
 # To disable optimizations while debugging, run `REPL_DEBUG=1 repl_www/build.sh`
 if [ "${REPL_DEBUG:-}" == "" ] && which wasm-opt
 then
     wasm-opt -Os --debuginfo repl_wasm/pkg/roc_repl_wasm_bg.wasm -o $WWW_ROOT/roc_repl_wasm_bg.wasm
+else
+    echo "wasm-opt is not installed. Skipping .wasm optimization."
+    cp -v repl_wasm/pkg/roc_repl_wasm_bg.wasm $WWW_ROOT
 fi
 
 # Copy the JS from wasm_bindgen, replacing its invalid `import` statement with a `var`.
diff --git a/www/build.sh b/www/build.sh
index 90b1d6f20e..cfc845f998 100755
--- a/www/build.sh
+++ b/www/build.sh
@@ -36,8 +36,7 @@ mv generated-docs/*.* www/build # move all the .js, .css, etc. files to build/
 mv generated-docs/ www/build/builtins # move all the folders to build/builtins/
 
 echo "Building Web REPL..."
-repl_www/build.sh
-cp -r repl_www/public/* www/build
+repl_www/build.sh www/build
 
 echo "Asset sizes:"
 ls -lh www/build/*

From 063f7d4a2664f704173d566315cb979f335aefac Mon Sep 17 00:00:00 2001
From: Anton-4 <17049058+Anton-4@users.noreply.github.com>
Date: Fri, 20 May 2022 12:02:54 +0200
Subject: [PATCH 15/16] Don't ignore warnings, remove fuse-ld arg

see https://github.com/rust-lang/cargo/issues/8010 on why I removed RUSTFLAGS="-Awarnings"
---
 www/build.sh | 6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)

diff --git a/www/build.sh b/www/build.sh
index cfc845f998..4ca72c5b26 100755
--- a/www/build.sh
+++ b/www/build.sh
@@ -21,10 +21,8 @@ echo 'Generating docs...'
 cargo --version
 rustc --version
 
-# We set RUSTFLAGS to -Awarnings to ignore warnings during this build,
-# because when building without "the" llvm feature (which is only ever done
-# for this exact use case), the result is lots of "unused" warnings!
-RUSTFLAGS=-Awarnings
+# removing `-C link-arg=-fuse-ld=lld` from RUSTFLAGS because this causes an error when compiling `roc_repl_wasm`
+RUSTFLAGS="-C target-cpu=native"
 
 # We set ROC_DOCS_ROOT_DIR=builtins so that links will be generated relative to
 # "/builtins/" rather than "/" - which is what we want based on how the server

From 1d3078cab3312a12f45911c5567ad1d5007757db Mon Sep 17 00:00:00 2001
From: Brian Carroll <brian.carroll.ireland@gmail.com>
Date: Fri, 20 May 2022 12:55:33 +0100
Subject: [PATCH 16/16] Remove debug code

---
 repl_www/build.sh | 10 ----------
 www/netlify.sh    |  2 --
 2 files changed, 12 deletions(-)

diff --git a/repl_www/build.sh b/repl_www/build.sh
index be68a157e5..23a8e9a1d5 100755
--- a/repl_www/build.sh
+++ b/repl_www/build.sh
@@ -18,16 +18,6 @@ fi
 WWW_ROOT="${1:-repl_www/public}"
 mkdir -p $WWW_ROOT
 
-# Debugging build scripts on CI
-lsb_release -a
-cargo --version
-rustc --version
-rustup show
-wasm-pack --version
-which wasm-opt && wasm-opt --version
-
-echo $PATH | tr ':' '\n'
-
 # We want a release build, but with debug info (to get stack traces for Wasm backend `todo!()`)
 # This configuration is called `--profiling`
 wasm-pack build --profiling --target web repl_wasm -- --features console_error_panic_hook -v
diff --git a/www/netlify.sh b/www/netlify.sh
index d973f943e7..20ea56bfc0 100644
--- a/www/netlify.sh
+++ b/www/netlify.sh
@@ -20,7 +20,5 @@ wget https://github.com/WebAssembly/binaryen/releases/download/version_108/${BIN
 tar --extract --gzip --file=${BINARYEN_DIRNAME}.tar.gz
 PATH="$(pwd)/${BINARYEN_DIRNAME}/bin:${PATH}"
 
-echo $PATH | tr ':' '\n'
-
 export PATH
 bash build.sh