diff --git a/CHANGELOG.md b/CHANGELOG.md
index 69262b3..a7226a4 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,3 +1,19 @@
+<a name="5.6.1"></a>
+## 5.6.1 (2023-09-18)
+
+#### Changed
+
+- Converted all exercises with assertions to test mode.
+
+#### Fixed
+
+- `cow1`: Reverted regression introduced by calling `to_mut` where it
+  shouldn't have been called, and clarified comment.
+- `primitive_types3`: Require at least an array of 100 elements.
+- Removed hint comments when no hint exists for the exercise.
+- `as_ref_mut`: Fixed a typo in a test function name.
+- `enums3`: Fixed formatting with `rustfmt`.
+
 <a name="5.6.0"></a>
 ## 5.6.0 (2023-09-04)
 
diff --git a/Cargo.lock b/Cargo.lock
index a8408ed..418032a 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -4,9 +4,9 @@ version = 3
 
 [[package]]
 name = "aho-corasick"
-version = "1.0.5"
+version = "0.7.20"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "0c378d78423fdad8089616f827526ee33c19f2fddbd5de1629152c9593ba4783"
+checksum = "cc936419f96fa211c1b9166887b38e5e40b19958e5b895be7c1f93adec7071ac"
 dependencies = [
  "memchr",
 ]
@@ -27,9 +27,9 @@ dependencies = [
 
 [[package]]
 name = "anstyle"
-version = "1.0.2"
+version = "1.0.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "15c4c2c83f81532e5845a733998b6971faca23490340a418e9b72a3ec9de12ea"
+checksum = "b84bf0a05bbb2a83e5eb6fa36bb6e87baa08193c35ff52bbf6b38d8af2890e46"
 
 [[package]]
 name = "anstyle-parse"
@@ -111,9 +111,9 @@ checksum = "baf1de4339761588bc0619e3cbc0120ee582ebb74b53b4efbf79117bd2da40fd"
 
 [[package]]
 name = "clap"
-version = "4.4.2"
+version = "4.4.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "6a13b88d2c62ff462f88e4a121f17a82c1af05693a2f192b5c38d14de73c19f6"
+checksum = "84ed82781cea27b43c9b106a979fe450a13a31aab0500595fb3fc06616de08e6"
 dependencies = [
  "clap_builder",
  "clap_derive",
@@ -157,15 +157,15 @@ checksum = "acbf1af155f9b9ef647e42cdc158db4b64a1b61f743629225fde6f3e0be2a7c7"
 
 [[package]]
 name = "console"
-version = "0.15.7"
+version = "0.15.5"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "c926e00cc70edefdc64d3a5ff31cc65bb97a3460097762bd23afb4d8145fccf8"
+checksum = "c3d79fbe8970a77e3e34151cc13d3b3e248aa0faaecb9f6091fa07ebefe5ad60"
 dependencies = [
  "encode_unicode",
  "lazy_static",
  "libc",
  "unicode-width",
- "windows-sys 0.45.0",
+ "windows-sys 0.42.0",
 ]
 
 [[package]]
@@ -200,14 +200,14 @@ checksum = "5443807d6dff69373d433ab9ef5378ad8df50ca6298caf15de6e52e24aaf54d5"
 
 [[package]]
 name = "filetime"
-version = "0.2.22"
+version = "0.2.20"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "d4029edd3e734da6fe05b6cd7bd2960760a616bd2ddd0d59a0124746d6272af0"
+checksum = "8a3de6e8d11b22ff9edc6d916f890800597d60f8b2da1caf2955c274638d6412"
 dependencies = [
  "cfg-if 1.0.0",
  "libc",
  "redox_syscall",
- "windows-sys 0.48.0",
+ "windows-sys 0.45.0",
 ]
 
 [[package]]
@@ -274,11 +274,11 @@ checksum = "95505c38b4572b2d910cecb0281560f54b440a19336cbbcb27bf6ce6adc6f5a8"
 
 [[package]]
 name = "home"
-version = "0.5.5"
+version = "0.5.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "5444c27eef6923071f7ebcc33e3444508466a76f7a2b93da00ed6e19f30c1ddb"
+checksum = "747309b4b440c06d57b0b25f2aee03ee9b5e5397d288c60e21fc709bb98a7408"
 dependencies = [
- "windows-sys 0.48.0",
+ "winapi 0.3.9",
 ]
 
 [[package]]
@@ -353,9 +353,9 @@ dependencies = [
 
 [[package]]
 name = "itoa"
-version = "1.0.9"
+version = "1.0.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "af150ab688ff2122fcef229be89cb50dd66af9e01a4ff320cc137eecc9bacc38"
+checksum = "453ad9f582a441959e5f0d088b02ce04cfe8d51a8eaf077f12ac6d3e94164ca6"
 
 [[package]]
 name = "kernel32-sys"
@@ -381,15 +381,18 @@ checksum = "830d08ce1d1d941e6b30645f1a0eb5643013d835ce3779a5fc208261dbe10f55"
 
 [[package]]
 name = "libc"
-version = "0.2.147"
+version = "0.2.140"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "b4668fb0ea861c1df094127ac5f1da3409a82116a4ba74fca2e58ef927159bb3"
+checksum = "99227334921fae1a979cf0bfdfcc6b3e5ce376ef57e16fb6fb3ea2ed6095f80c"
 
 [[package]]
 name = "log"
-version = "0.4.20"
+version = "0.4.17"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "b5e6163cb8c49088c2c36f57875e58ccd8c87c7427f7fbd50ea6710b2f3f2e8f"
+checksum = "abb12e687cfb44aa40f41fc3978ef76448f9b6038cad6aef4259d3c095a2382e"
+dependencies = [
+ "cfg-if 1.0.0",
+]
 
 [[package]]
 name = "memchr"
@@ -442,9 +445,9 @@ dependencies = [
 
 [[package]]
 name = "net2"
-version = "0.2.39"
+version = "0.2.38"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "b13b648036a2339d06de780866fbdfda0dde886de7b3af2ddeba8b14f4ee34ac"
+checksum = "74d0df99cfcd2530b2e694f6e17e7f37b8e26bb23983ac530c0c97408837c631"
 dependencies = [
  "cfg-if 0.1.10",
  "libc",
@@ -477,9 +480,9 @@ dependencies = [
 
 [[package]]
 name = "num-traits"
-version = "0.2.16"
+version = "0.2.15"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "f30b0abd723be7e2ffca1272140fac1a2f084c77ec3e123c192b66af1ee9e6c2"
+checksum = "578ede34cf02f8924ab9447f50c28075b4d3e5b269972345e7e0372b38c6cdcd"
 dependencies = [
  "autocfg",
 ]
@@ -529,40 +532,39 @@ dependencies = [
 
 [[package]]
 name = "proc-macro2"
-version = "1.0.66"
+version = "1.0.53"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "18fb31db3f9bddb2ea821cde30a9f70117e3f119938b5ee630b7403aa6e2ead9"
+checksum = "ba466839c78239c09faf015484e5cc04860f88242cff4d03eb038f04b4699b73"
 dependencies = [
  "unicode-ident",
 ]
 
 [[package]]
 name = "quote"
-version = "1.0.33"
+version = "1.0.26"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "5267fca4496028628a95160fc423a33e8b2e6af8a5302579e322e4b520293cae"
+checksum = "4424af4bf778aae2051a77b60283332f386554255d722233d09fbfc7e30da2fc"
 dependencies = [
  "proc-macro2",
 ]
 
 [[package]]
 name = "redox_syscall"
-version = "0.3.5"
+version = "0.2.16"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "567664f262709473930a4bf9e51bf2ebf3348f2e748ccc50dea20646858f8f29"
+checksum = "fb5a58c1855b4b6819d59012155603f0b22ad30cad752600aadfcb695265519a"
 dependencies = [
  "bitflags",
 ]
 
 [[package]]
 name = "regex"
-version = "1.9.5"
+version = "1.7.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "697061221ea1b4a94a624f67d0ae2bfe4e22b8a17b6a192afb11046542cc8c47"
+checksum = "cce168fea28d3e05f158bda4576cf0c844d5045bc2cc3620fa0292ed5bb5814c"
 dependencies = [
  "aho-corasick",
  "memchr",
- "regex-automata",
  "regex-syntax",
 ]
 
@@ -571,21 +573,16 @@ name = "regex-automata"
 version = "0.3.8"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "c2f401f4955220693b56f8ec66ee9c78abffd8d1c4f23dc41a23839eb88f0795"
-dependencies = [
- "aho-corasick",
- "memchr",
- "regex-syntax",
-]
 
 [[package]]
 name = "regex-syntax"
-version = "0.7.5"
+version = "0.6.29"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "dbb5fb1acd8a1a18b3dd5be62d25485eb770e05afb408a9627d14d451bae12da"
+checksum = "f162c6dd7b008981e4d40210aca20b4bd0f9b60ca9271061b07f78537722f2e1"
 
 [[package]]
 name = "rustlings"
-version = "5.6.0"
+version = "5.6.1"
 dependencies = [
  "assert_cmd",
  "clap",
@@ -603,9 +600,9 @@ dependencies = [
 
 [[package]]
 name = "ryu"
-version = "1.0.15"
+version = "1.0.13"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "1ad4cc8da4ef723ed60bced201181d83791ad433213d8c24efffda1eec85d741"
+checksum = "f91339c0467de62360649f8d3e185ca8de4224ff281f66000de5eb2a77a79041"
 
 [[package]]
 name = "same-file"
@@ -618,18 +615,18 @@ dependencies = [
 
 [[package]]
 name = "serde"
-version = "1.0.188"
+version = "1.0.158"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "cf9e0fcba69a370eed61bcf2b728575f726b50b55cba78064753d708ddc7549e"
+checksum = "771d4d9c4163ee138805e12c710dd365e4f44be8be0503cb1bb9eb989425d9c9"
 dependencies = [
  "serde_derive",
 ]
 
 [[package]]
 name = "serde_derive"
-version = "1.0.188"
+version = "1.0.158"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "4eca7ac642d82aa35b60049a6eccb4be6be75e599bd2e9adb5f875a737654af2"
+checksum = "e801c1712f48475582b7696ac71e0ca34ebb30e09338425384269d9717c62cad"
 dependencies = [
  "proc-macro2",
  "quote",
@@ -638,9 +635,9 @@ dependencies = [
 
 [[package]]
 name = "serde_json"
-version = "1.0.105"
+version = "1.0.94"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "693151e1ac27563d6dbcec9dee9fbd5da8539b20fa14ad3752b2e6d363ace360"
+checksum = "1c533a59c9d8a93a09c6ab31f0fd5e5f4dd1b8fc9434804029839884765d04ea"
 dependencies = [
  "itoa",
  "ryu",
@@ -658,9 +655,9 @@ dependencies = [
 
 [[package]]
 name = "slab"
-version = "0.4.9"
+version = "0.4.8"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "8f92a496fb766b417c996b9c5e57daf2f7ad3b0bebe1ccfca4856390e3d3bb67"
+checksum = "6528351c9bc8ab22353f9d776db39a20288e8d6c37ef8cfe3317cf875eecfc2d"
 dependencies = [
  "autocfg",
 ]
@@ -673,9 +670,9 @@ checksum = "73473c0e59e6d5812c5dfe2a064a6444949f089e20eec9a2e5506596494e4623"
 
 [[package]]
 name = "syn"
-version = "2.0.31"
+version = "2.0.8"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "718fa2415bcb8d8bd775917a1bf12a7931b6dfa890753378538118181e0cb398"
+checksum = "bcc02725fd69ab9f26eab07fad303e2497fad6fb9eba4f96c4d1687bdf704ad9"
 dependencies = [
  "proc-macro2",
  "quote",
@@ -690,9 +687,9 @@ checksum = "3369f5ac52d5eb6ab48c6b4ffdc8efbcad6b89c765749064ba298f2c68a16a76"
 
 [[package]]
 name = "toml"
-version = "0.7.6"
+version = "0.7.8"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "c17e963a819c331dcacd7ab957d80bc2b9a9c1e71c804826d2f283dd65306542"
+checksum = "dd79e69d3b627db300ff956027cc6c3798cef26d22526befdfcd12feeb6d2257"
 dependencies = [
  "serde",
  "serde_spanned",
@@ -711,9 +708,9 @@ dependencies = [
 
 [[package]]
 name = "toml_edit"
-version = "0.19.14"
+version = "0.19.15"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "f8123f27e969974a3dfba720fdb560be359f57b44302d280ba72e76a74480e8a"
+checksum = "1b5bb770da30e5cbfde35a2d7b9b8a2c4b8ef89548a7a6aeab5c9a576e3e7421"
 dependencies = [
  "indexmap",
  "serde",
@@ -724,9 +721,9 @@ dependencies = [
 
 [[package]]
 name = "unicode-ident"
-version = "1.0.11"
+version = "1.0.8"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "301abaae475aa91687eb82514b328ab47a211a533026cb25fc3e519b86adfc3c"
+checksum = "e5464a87b239f13a63a501f2701565754bae92d243d4bb7eb12f6d57d2269bf4"
 
 [[package]]
 name = "unicode-width"
@@ -802,6 +799,21 @@ version = "0.4.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "712e227841d057c1ee1cd2fb22fa7e5a5461ae8e48fa2ca79ec42cfc1931183f"
 
+[[package]]
+name = "windows-sys"
+version = "0.42.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "5a3e1820f08b8513f676f7ab6c1f99ff312fb97b553d30ff4dd86f9f15728aa7"
+dependencies = [
+ "windows_aarch64_gnullvm 0.42.2",
+ "windows_aarch64_msvc 0.42.2",
+ "windows_i686_gnu 0.42.2",
+ "windows_i686_msvc 0.42.2",
+ "windows_x86_64_gnu 0.42.2",
+ "windows_x86_64_gnullvm 0.42.2",
+ "windows_x86_64_msvc 0.42.2",
+]
+
 [[package]]
 name = "windows-sys"
 version = "0.45.0"
diff --git a/Cargo.toml b/Cargo.toml
index d64ef75..a055d4f 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -1,7 +1,7 @@
 [package]
 name = "rustlings"
 description = "Small exercises to get you used to reading and writing Rust code!"
-version = "5.6.0"
+version = "5.6.1"
 authors = [
   "Liv <mokou@fastmail.com>",
   "Carol (Nichols || Goulding) <carol.nichols@gmail.com>",
diff --git a/README.md b/README.md
index a16f753..8fac7a2 100644
--- a/README.md
+++ b/README.md
@@ -41,8 +41,8 @@ This will install Rustlings and give you access to the `rustlings` command. Run
 Basically: Clone the repository at the latest tag, finally run `nix develop` or `nix-shell`.
 
 ```bash
-# find out the latest version at https://github.com/rust-lang/rustlings/releases/latest (on edit 5.6.0)
-git clone -b 5.6.0 --depth 1 https://github.com/rust-lang/rustlings
+# find out the latest version at https://github.com/rust-lang/rustlings/releases/latest (on edit 5.6.1)
+git clone -b 5.6.1 --depth 1 https://github.com/rust-lang/rustlings
 cd rustlings
 # if nix version > 2.3
 nix develop
@@ -79,8 +79,8 @@ If you get a permission denied message, you might have to exclude the directory
 Basically: Clone the repository at the latest tag, run `cargo install --path .`.
 
 ```bash
-# find out the latest version at https://github.com/rust-lang/rustlings/releases/latest (on edit 5.6.0)
-git clone -b 5.6.0 --depth 1 https://github.com/rust-lang/rustlings
+# find out the latest version at https://github.com/rust-lang/rustlings/releases/latest (on edit 5.6.1)
+git clone -b 5.6.1 --depth 1 https://github.com/rust-lang/rustlings
 cd rustlings
 cargo install --force --path .
 ```
diff --git a/flake.nix b/flake.nix
index 94f4177..152d38e 100644
--- a/flake.nix
+++ b/flake.nix
@@ -22,7 +22,7 @@
         rustlings =
           pkgs.rustPlatform.buildRustPackage {
             name = "rustlings";
-            version = "5.6.0";
+            version = "5.6.1";
 
             buildInputs = cargoBuildInputs;
             nativeBuildInputs = [pkgs.git];