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-rw-r--r--tvix/docs/.gitignore2
-rw-r--r--tvix/docs/Makefile12
-rw-r--r--tvix/docs/component-flow.puml60
-rw-r--r--tvix/docs/components.md160
-rw-r--r--tvix/docs/default.nix47
-rw-r--r--tvix/docs/lang-version.md60
-rw-r--r--tvix/docs/language-spec.md78
-rw-r--r--tvix/docs/value-pointer-equality.md202
8 files changed, 621 insertions, 0 deletions
diff --git a/tvix/docs/.gitignore b/tvix/docs/.gitignore
new file mode 100644
index 000000000000..77699ee8a3f7
--- /dev/null
+++ b/tvix/docs/.gitignore
@@ -0,0 +1,2 @@
+*.svg
+*.html
diff --git a/tvix/docs/Makefile b/tvix/docs/Makefile
new file mode 100644
index 000000000000..ba9e2bdef6d3
--- /dev/null
+++ b/tvix/docs/Makefile
@@ -0,0 +1,12 @@
+all: build
+
+puml:
+	plantuml *.puml -tsvg
+
+html:
+	pandoc *.md -f markdown --self-contained -t html -s -o tvix.html --csl=${CSL}
+
+build: puml html
+
+clean:
+	rm -f *.tex *.pdf *.png *.svg
diff --git a/tvix/docs/component-flow.puml b/tvix/docs/component-flow.puml
new file mode 100644
index 000000000000..5b6d79b82313
--- /dev/null
+++ b/tvix/docs/component-flow.puml
@@ -0,0 +1,60 @@
+@startuml
+
+title Tvix build flow
+
+actor User
+participant CLI
+participant "Coordinator" as Coord
+participant "Evaluator" as Eval
+database Store
+participant "Builder" as Build
+
+note over CLI,Eval
+    Typically runs locally on the invoking machine
+end note
+/ note over Store, Build
+    Can be either local or remote
+end note
+
+User-->CLI: User initiates build of `hello` (analogous to `nix-build -f '<nixpkgs>' -A hello`)
+
+CLI-->Coord: CLI invokes coordinator
+
+Coord-->Eval: Sends message to start evaluation of `<nixpkgs>` (path lookup) with attribute `hello`
+note right: The paths to the evaluator are local file system paths
+
+Coord<--Eval: Yields derivations to be built
+note right
+    Immediately starts streaming derivations as they are instantiated across
+    the dependency graph so they can be built while the evaluation is still running.
+
+    There are two types of build requests: One for regular "fire and forget" builds,
+    and another for IFD (import from derivation).
+
+    These are distinct because IFD needs to be fed back into the evaluator for
+    further processing while a regular build does not.
+end note
+
+loop while has more derivations
+
+    Coord-->Store: Check if desired paths are in store
+    alt Store has path
+        Coord<--Store: Success response
+    else Store does not have path
+        Coord-->Build: Request derivation to be built
+
+        alt Build failure
+            Coord<--Build: Fail response
+            note left: It's up to the coordinator whether to exit on build failure
+        else Build success
+            Build-->Store: Push outputs to store
+            Build<--Coord: Send success & pushed response
+        end
+
+    end
+end
+
+CLI<--Coord: Respond success/fail
+User<--CLI: Exit success/fail
+
+@enduml
diff --git a/tvix/docs/components.md b/tvix/docs/components.md
new file mode 100644
index 000000000000..a7d61948c2fa
--- /dev/null
+++ b/tvix/docs/components.md
@@ -0,0 +1,160 @@
+---
+title: "Tvix - Architecture & data flow"
+numbersections: true
+author:
+- adisbladis
+- flokli
+- tazjin
+email:
+- adis@blad.is
+- mail@tazj.in
+lang: en-GB
+classoption:
+- twocolumn
+header-includes:
+- \usepackage{caption, graphicx, tikz, aeguill, pdflscape}
+---
+
+# Background
+
+We intend for Tvix tooling to be more decoupled than the existing,
+monolithic Nix implementation. In practice, we expect to gain several
+benefits from this, such as:
+
+- Ability to use different builders
+- Ability to use different store implementations
+- No monopolisation of the implementation, allowing users to replace
+  components that they are unhappy with (up to and including the
+  language evaluator)
+- Less hidden intra-dependencies between tools due to explicit RPC/IPC
+  boundaries
+
+Communication between different components of the system will use
+gRPC. The rest of this document outlines the components.
+
+# Components
+
+## Coordinator
+
+*Purpose:* The coordinator (in the simplest case, the Tvix CLI tool)
+oversees the flow of a build process and delegates tasks to the right
+subcomponents. For example, if a user runs the equivalent of
+`nix-build` in a folder containing a `default.nix` file, the
+coordinator will invoke the evaluator, pass the resulting derivations
+to the builder and coordinate any necessary store interactions (for
+substitution and other purposes).
+
+While many users are likely to use the CLI tool as their primary
+method of interacting with Tvix, it is not unlikely that alternative
+coordinators (e.g. for a distributed, "Nix-native" CI system) would be
+implemented. To facilitate this, we are considering implementing the
+coordinator on top of a state-machine model that would make it
+possible to reuse the FSM logic without tying it to any particular
+kind of application.
+
+## Evaluator
+
+*Purpose:* Eval takes care of evaluating Nix code. In a typical build
+flow it would be responsible for producing derivations. It can also be
+used as a standalone tool, for example, in use-cases where Nix is used
+to generate configuration without any build or store involvement.
+
+*Requirements:* For now, it will run on the machine invoking the build
+command itself. We give it filesystem access to handle things like
+imports or `builtins.readFile`.
+
+To support IFD, the Evaluator also needs access to store paths. This
+could be implemented by having the coordinator provide an interface to retrieve
+files from a store path, or by ensuring a "realized version of the store" is
+accessible by the evaluator (this could be a FUSE filesystem, or the "real"
+/nix/store on disk.
+
+We might be okay with running the evaluator with filesystem access for now and
+can extend the interface if the need arises.
+
+## Builder
+
+*Purpose:* A builder receives derivations from the coordinator and
+builds them.
+
+By making builder a standardised interface it's possible to make the
+sandboxing mechanism used by the build process pluggable.
+
+Nix is currently using a hard-coded
+[libseccomp](https://github.com/seccomp/libseccomp) based sandboxing
+mechanism and another one based on
+[sandboxd](https://www.unix.com/man-page/mojave/8/sandboxd/) on macOS.
+These are only separated by [compiler preprocessor
+macros](https://gcc.gnu.org/onlinedocs/cpp/Ifdef.html) within the same
+source files despite having very little in common with each other.
+
+This makes experimentation with alternative backends difficult and
+porting Nix to other platforms harder than it has to be. We want to
+write a new Linux builder which uses
+[OCI](https://github.com/opencontainers/runtime-spec), the current
+dominant Linux containerisation technology, by default.
+
+With a well-defined builder abstraction, it's also easy to imagine
+other backends such as a Kubernetes-based one in the future.
+
+The environment in which builds happen is currently very Nix-specific. We might
+want to avoid having to maintain all the intricacies of a Nix-specific
+sandboxing environment in every builder, and instead only provide a more
+generic interface, receiving build requests (and have the coordinator translate
+derivations to that format). [^1]
+
+To build, the builder needs to be able to mount all build inputs into the build
+environment. For this, it needs the store to expose a filesystem interface.
+
+## Store
+
+*Purpose:* Store takes care of storing build results. It provides a
+unified interface to get store paths and upload new ones, as well as querying
+for the existence of a store path and its metadata (references, signatures, …).
+
+Tvix natively uses an improved store protocol. Instead of transferring around
+NAR files, which don't provide an index and don't allow seekable access, a
+concept similar to git tree hashing is used.
+
+This allows more granular substitution, chunk reusage and parallel download of
+individual files, reducing bandwidth usage.
+As these chunks are content-addressed, it opens up the potential for
+peer-to-peer trustless substitution of most of the data, as long as we sign the
+root of the index.
+
+Tvix still keeps the old-style signatures, NAR hashes and NAR size around. In
+the case of NAR hash / NAR size, this data is strictly required in some cases.
+The old-style signatures are valuable for communication with existing
+implementations.
+
+Old-style binary caches (like cache.nixos.org) can still be exposed via the new
+interface, by doing on-the-fly (re)chunking/ingestion.
+
+Most likely, there will be multiple implementations of store, some storing
+things locally, some exposing a "remote view".
+
+A few possible ones that come to mind are:
+
+- Local store
+- SFTP/ GCP / S3 / HTTP
+- NAR/NARInfo protocol: HTTP, S3
+
+A remote Tvix store can be connected by simply connecting to its gRPC
+interface, possibly using SSH tunneling, but there doesn't need to be an
+additional "wire format" like the Nix `ssh(+ng)://` protocol.
+
+Settling on one interface allows composition of stores, meaning it becomes
+possible to express substitution from remote caches as a proxy layer.
+
+It'd also be possible to write a FUSE implementation on top of the RPC
+interface, exposing a lazily-substituting /nix/store mountpoint. Using this in
+remote build context dramatically reduces the amount of data transferred to a
+builder, as only the files really accessed during the build are substituted.
+
+# Figures
+
+![component flow](./component-flow.svg)
+
+[^1]: There have already been some discussions in the Nix community, to switch
+  to REAPI:
+  https://discourse.nixos.org/t/a-proposal-for-replacing-the-nix-worker-protocol/20926/22
diff --git a/tvix/docs/default.nix b/tvix/docs/default.nix
new file mode 100644
index 000000000000..016d641df59f
--- /dev/null
+++ b/tvix/docs/default.nix
@@ -0,0 +1,47 @@
+{ pkgs, lib, ... }:
+
+let
+
+  tl = pkgs.texlive.combine {
+    inherit (pkgs.texlive) scheme-medium wrapfig ulem capt-of
+      titlesec preprint enumitem paralist ctex environ svg
+      beamer trimspaces zhnumber changepage framed pdfpages
+      fvextra minted upquote ifplatform xstring;
+  };
+
+  csl = pkgs.fetchurl {
+    name = "numeric.csl";
+    url = "https://gist.githubusercontent.com/bwiernik/8c6f39cf51ceb3a03107/raw/1d75c2d62113ffbba6ed03a47ad99bde86934f2b/APA%2520Numeric";
+    sha256 = "1yfhhnhbzvhrv93baz98frmgsx5y442nzhb0l956l4j35fb0cc3h";
+  };
+
+in
+pkgs.stdenv.mkDerivation {
+  pname = "tvix-doc";
+  version = "0.1";
+
+  outputs = [ "out" "svg" ];
+
+  src = lib.cleanSource ./.;
+
+  CSL = csl;
+
+  nativeBuildInputs = [
+    pkgs.pandoc
+    pkgs.plantuml
+    tl
+  ];
+
+  installPhase = ''
+    runHook preInstall
+
+    mkdir -p $out
+    cp -v *.html $out/
+
+    mkdir -p $svg
+    cp -v *.svg $svg/
+
+    runHook postSubmit
+  '';
+
+}
diff --git a/tvix/docs/lang-version.md b/tvix/docs/lang-version.md
new file mode 100644
index 000000000000..c09422a5897a
--- /dev/null
+++ b/tvix/docs/lang-version.md
@@ -0,0 +1,60 @@
+# Nix language version history
+
+The Nix language (“Nix”) has its own versioning mechanism independent from its
+most popular implementation (“C++ Nix”): `builtins.langVersion`. It has been
+increased whenever the language has changed syntactically or semantically in a
+way that would not be introspectable otherwise. In particular, this does not
+include addition (or removal) of `builtins`, as this can be introspected using
+standard attribute set operations.
+
+Changes to `builtins.langVersion` are best found by viewing the git history of
+C++ Nix using `git log -G 'mkInt\\(v, [0-9]\\)'` for `builtins.langVersion` < 7.
+After that point `git log -G 'v\\.mkInt\\([0-9]+\\)'` should work. To reduce the
+amount of false positives, specify the version number you are interested in
+explicitly.
+
+## 1
+
+The first version of the Nix language is its state at the point when
+`builtins.langVersion` was added in [8b8ee53] which was first released
+as part of C++ Nix 1.2.
+
+## 2
+
+Nix version 2 changed the behavior of `builtins.storePath`: It would now [try to
+substitute the given path if missing][storePath-substitute], instead of creating
+an evaluation failure. `builtins.langVersion` was increased in [e36229d].
+
+## 3
+
+Nix version 3 changed the behavior of the `==` behavior. Strings would now be
+considered [equal even if they had differing string context][equal-no-ctx].
+
+## 4
+
+Nix version 4 [added the float type][float] to the language.
+
+## 5
+
+The [increase of `builtins.langVersion` to 5][langVersion-5] did not signify a
+language change, but added support for structured attributes to the Nix daemon.
+Eelco Dolstra writes as to what changed:
+
+> The structured attributes support. Unfortunately that's not so much a language
+> change as a build.cc (i.e. daemon) change, but we don't really have a way to
+> express that...
+
+Probably `builtins.nixVersion` (which was added in version 1) should have been
+used instead.
+
+## 6
+
+Nix version 6 added support for [comparing two lists][list-comparison].
+
+[8b8ee53]: https://github.com/nixos/nix/commit/8b8ee53bc73769bb25d967ba259dabc9b23e2e6f
+[storePath-substitute]: https://github.com/nixos/nix/commit/22d665019a3770148929b7504c73bcdbe025ec12
+[e36229d]: https://github.com/nixos/nix/commit/e36229d27f9ab508e0abf1892f3e8c263d2f8c58
+[equal-no-ctx]: https://github.com/nixos/nix/commit/ee7fe64c0ac00f2be11604a2a6509eb86dc19f0a
+[float]: https://github.com/nixos/nix/commit/14ebde52893263930cdcde1406cc91cc5c42556f
+[langVersion-5]: https://github.com/nixos/nix/commit/8191992c83bf4387b03c5fdaba818dc2b520462d
+[list-comparison]: https://github.com/nixos/nix/commit/09471d2680292af48b2788108de56a8da755d661
diff --git a/tvix/docs/language-spec.md b/tvix/docs/language-spec.md
new file mode 100644
index 000000000000..a71437493307
--- /dev/null
+++ b/tvix/docs/language-spec.md
@@ -0,0 +1,78 @@
+---
+title: "Specification of the Nix language"
+numbersections: true
+author:
+- tazjin
+email:
+- tazjin@tvl.su
+lang: en-GB
+---
+
+The Nix Language
+================
+
+WARNING: This document is a work in progress. Please keep an eye on
+[`topic:nix-spec`](https://cl.tvl.fyi/q/topic:nix-spec) for ongoing
+CLs.
+
+Nix is a general-purpose, functional programming language which this
+document aims to describe.
+
+## Background
+
+Nix was designed and implemented as part of the [Nix package
+manager](https://nixos.org/nix). It is primarily used for generating
+so-called [*derivations*](#derivations), which are data structures
+describing how to build a package.
+
+The language has been described in the
+[thesis](https://edolstra.github.io/pubs/phd-thesis.pdf) introducing
+the package manager, but only on a high-level. At the time of writing,
+Nix is informally specified (via its only complete implementation in
+the package manager) and there is no complete overview over its -
+sometimes surprising - semantics.
+
+The primary project written in Nix is
+[nixpkgs](https://github.com/NixOS/nixpkgs/). Uncertainties in the
+process of writing this specification are resolved by investigating
+patterns in nixpkgs, which we consider canonical. The code in nixpkgs
+uses a reasonable subset of the features exposed by the current
+implementation, some of which are *accidental*, and is thus more
+useful for specifying how the language should work.
+
+## Introduction to Nix
+
+Nix is a general-purpose, partially lazy, functional programming
+language which provides higher-order functions, type reflection,
+primitive data types such as integers, strings and floats, and
+compound data structures such as lists and attribute sets.
+
+Nix has syntactic sugar for common operations, such as those for
+attribute sets, and also provides a wide range of built-in functions
+which have organically accumulated over time.
+
+Nix has a variety of legacy features that are not in practical use,
+but are documented in sections of this specification for the sake of
+completeness.
+
+This document describes the syntax and abstract semantics of the Nix
+language, but leaves out implementation details about how Nix can be
+interpreted/compiled/analysed etc.
+
+### Program structure
+
+This section describes the semantic structure of Nix, and how it
+relates to the rest of the specification.
+
+Each Nix program is a single [*expression*](#expressions) denoting a
+[*value*](#values) (commonly a [*function*](#functions)). Each value
+has a [*type*](#types), however this type is not statically known.
+
+Nix code is modularised through the use of the
+[*import*](#builtins-import) built-in function. No separate module
+system exists.
+
+In addition to chapters describing the building blocks mentioned
+above, this specificiation also describes the [*syntax*](#syntax), the
+available [built-in functions](#builtins), [*error handling*](#errors)
+and known [*deficiencies*](#deficiencies) in the language.
diff --git a/tvix/docs/value-pointer-equality.md b/tvix/docs/value-pointer-equality.md
new file mode 100644
index 000000000000..78b1466f3a8f
--- /dev/null
+++ b/tvix/docs/value-pointer-equality.md
@@ -0,0 +1,202 @@
+# Value Pointer Equality in Nix
+
+## Introduction
+
+It is a piece of semi-obscure Nix trivia that while functions are generally not
+comparable, they can be compared in certain situations. This is actually quite an
+important fact, as it is essential for the evaluation of nixpkgs: The attribute sets
+used to represent platforms in nixpkgs, like `stdenv.buildPlatform`, contain functions,
+such as `stdenv.buildPlatform.canExecute`. When writing cross logic, one invariably
+ends up writing expressions that compare these sets, e.g. `stdenv.buildPlatform !=
+stdenv.hostPlatform`. Since attribute set equality is the equality of their attribute
+names and values, we also end up comparing the functions within them.  We can summarize
+the relevant part of this behavior for platform comparisons in the following (true)
+Nix expressions:
+
+* `stdenv.hostPlatform.canExecute != stdenv.hostPlatform.canExecute`
+* `stdenv.hostPlatform == stdenv.hostPlatform`
+
+This fact is commonly referred to as pointer equality of functions (or function pointer
+equality) which is not an entirely accurate name, as we'll see. This account of the
+behavior states that, while functions are incomparable in general, they are comparable
+insofar, as they occupy the same spot in an attribute set.
+
+However, [a maybe lesser known trick][puck-issue] is to write a function such as the
+following to allow comparing functions:
+
+```nix
+let
+  pointerEqual = lhs: rhs: { x = lhs; } == { x = rhs; };
+
+  f = name: "Hello, my name is ${name}";
+  g = name: "Hello, my name is ${name}";
+in
+[
+  (pointerEqual f f) # => true
+  (pointerEqual f g) # => false
+]
+```
+
+Here, clearly, the function is not contained at the same position in one and the same
+attribute set, but at the same position in two entirely different attribute sets. We can
+also see that we are not comparing the functions themselves (e.g. their AST), but
+rather if they are the same individual value (i.e. pointer equal).
+
+So what is _actually_ going on?
+
+## Nix (pointer) Equality in C++ Nix
+
+TIP: The summary presented here is up-to-date as of 2022-11-23 and was tested with Nix 2.3 and 2.11.
+
+The function implementing equality in C++ Nix is `EvalState::eqValues` which starts with
+[the following bit of code][eqValues-pointer-eq]:
+
+```cpp
+bool EvalState::eqValues(Value & v1, Value & v2)
+{
+    forceValue(v1);
+    forceValue(v2);
+
+    /* !!! Hack to support some old broken code that relies on pointer
+       equality tests between sets.  (Specifically, builderDefs calls
+       uniqList on a list of sets.)  Will remove this eventually. */
+    if (&v1 == &v2) return true;
+```
+
+So this immediately looks more like pointer equality of arbitrary *values* instead of functions. In fact
+there is [no special code facilitating function equality][eqValues-function-eq]:
+
+```cpp
+        /* Functions are incomparable. */
+        case nFunction:
+            return false;
+```
+
+So one takeaway of this is that pointer equality is neither dependent on functions nor attribute sets.
+In fact, we can also write our `pointerEqual` function as:
+
+```nix
+lhs: rhs: [ lhs ] == [ rhs ]
+```
+
+It's interesting that `EvalState::eqValues` forces the left and right-hand value before trying pointer
+equality. It explains that `let x = throw ""; in x == x` does not evaluate successfully, but it is puzzling why
+`let f = x: x; in f == f` does not return `true`. In fact, why do we need to wrap the values in a list or
+attribute set at all for our `pointerEqual` function to work?
+
+The answer lies in [the code that evaluates `ExprOpEq`][ExprOpEq],
+i.e. an expression involving the `==` operator:
+
+```cpp
+void ExprOpEq::eval(EvalState & state, Env & env, Value & v)
+{
+    Value v1; e1->eval(state, env, v1);
+    Value v2; e2->eval(state, env, v2);
+    v.mkBool(state.eqValues(v1, v2));
+}
+```
+
+As you can see, two _distinct_ `Value` structs are created, so they can never be pointer equal even
+if the `union` inside points to the same bit of memory. We can thus understand what actually happens
+when we check the equality of an attribute set (or list), by looking at the following expression:
+
+```nix
+let
+  x = { name = throw "nameless"; };
+in
+
+x == x # => causes an evaluation error
+```
+
+Because `x` can't be pointer equal, as it'll end up in the distinct structs `v1` and `v2`, it needs to be compared
+by value. For this reason, the `name` attribute will be forced and an evaluation error caused.
+If we rewrite the expression to use…
+
+```nix
+{ inherit x; } == { inherit x; } # => true
+```
+
+…, it'll work: The two attribute sets are compared by value, but their `x` attribute turns out to be pointer
+equal _after_ forcing it. This does not throw, since forcing an attribute set does not force its attributes'
+values (as forcing a list doesn't force its elements).
+
+As we have seen, pointer equality can not only be used to compare function values, but also other
+otherwise incomparable values, such as lists and attribute sets that would cause an evaluation
+error if they were forced recursively. We can even switch out the `throw` for an `abort`. The limitation is
+of course that we need to use a value that behaves differently depending on whether it is forced
+“normally” (think `builtins.seq`) or recursively (think `builtins.deepSeq`), so thunks will generally be
+evaluated before pointer equality can kick into effect.
+
+## Summary
+
+When comparing two Nix values, we must force both of them (non-recursively!), but are
+allowed to short-circuit the comparison based on pointer equality, i.e. if they are at
+the same exact value in memory, they are deemed equal immediately. This is completely
+independent of what type of value they are. If they are not pointer equal, they are
+(recursively) compared by value as expected.
+
+However, when evaluating the Nix expression `a == b`, we *must* invoke our implementation's
+value equality function in a way that `a` and `b` themselves can never be deemed pointer equal.
+Any values we encounter while recursing during the equality check must be compared by
+pointer as described above, though.
+
+## Other Comparisons
+
+The `!=` operator uses `EvalState::eqValues` internally as well, so it behaves exactly as `!(a == b)`.
+
+The `>`, `<`, `>=` and `<=` operators all desugar to [CompareValues][] eventually
+which generally looks at the value type before comparing. It does, however, rely on
+`EvalState::eqValues` for list comparisons, so it is possible to compare lists with
+e.g. functions in them, as long as they are equal by pointer:
+
+```nix
+let
+  f = x: x + 42;
+in
+
+[
+  ([ f 2 ] > [ f 1 ]) # => true
+  ([ f 2 ] > [ (x: x) 1]) # => error: cannot compare a function with a function
+]
+```
+
+Finally, since `builtins.elem` relies on `EvalState::eqValues`, you can check for
+a function by pointer equality:
+
+```nix
+let
+  f = x: f x;
+in
+builtins.elem f [ f 2 3 ] # => true
+```
+
+## Stability of the Feature
+
+Keen readers will have noticed the following comment in the C++ Nix source code,
+indicating that pointer comparison may be removed in the future.
+
+```cpp
+    /* !!! Hack to support some old broken code that relies on pointer
+       equality tests between sets.  (Specifically, builderDefs calls
+       uniqList on a list of sets.)  Will remove this eventually. */
+```
+
+Now, I can't speak for the upstream C++ Nix developers, but sure can speculate.
+As already pointed out, this feature is currently needed for evaluating nixpkgs.
+While its use could realistically be eliminated (only bothersome spot is probably
+the `emulator` function, but that should also be doable), removing the feature
+would seriously compromise C++ Nix's ability to evaluate historical nixpkgs
+revision which is arguably a strength of the system.
+
+Another indication that it is likely here to stay is that it has already
+[outlived builderDefs][], even though
+it was (apparently) reintroduced just for this use case. More research into
+the history of this feature would still be prudent, especially the reason for
+its original introduction (maybe performance?).
+
+[puck-issue]: https://github.com/NixOS/nix/issues/3371
+[eqValues-pointer-eq]: https://github.com/NixOS/nix/blob/05d0892443bbe92a6b6a1ee7b1d37ea05782d918/src/libexpr/eval.cc#L2342-L2350
+[eqValues-function-eq]: https://github.com/NixOS/nix/blob/05d0892443bbe92a6b6a1ee7b1d37ea05782d918/src/libexpr/eval.cc#L2405-L2407
+[ExprOpEq]: https://github.com/NixOS/nix/blob/05d0892443bbe92a6b6a1ee7b1d37ea05782d918/src/libexpr/eval.cc#L1856-L1861
+[outlived builderDefs]: https://github.com/NixOS/nixpkgs/issues/4210
+[CompareValues]: https://github.com/NixOS/nix/blob/master/src/libexpr/primops.cc#L536-L574
generated by cgit-pink 1.4.1 (git 2.44.2) at 2024-11-29T14·21+0000