feat(tvix/derivation): also fail if output name is called `drv` r/5694

`drv` is an invalid output name too, as this would cause a
`builtins.derivation` call to return an attrset with a `drvPath` key
(which already exists) and has a different meaning.

Also handle errors during store path construction, and return our own
error type, instead of the ParseStorePathError.

Change-Id: Ib7952dde1d5cf18a0e210928df7c57b5939b7678
Reviewed-on: https://cl.tvl.fyi/c/depot/+/7850
Tested-by: BuildkiteCI
Reviewed-by: tazjin <tazjin@tvl.su>
Autosubmit: flokli <flokli@flokli.de>

1 files changed, 11 insertions, 5 deletions

diff --git a/tvix/derivation/src/derivation.rs b/tvix/derivation/src/derivation.rs
index 1e2605f5b931..daccfad6c42e 100644
--- a/tvix/derivation/src/derivation.rs
+++ b/tvix/derivation/src/derivation.rs
@@ -1,12 +1,12 @@
-use crate::nix_hash;
 use crate::output::{Hash, Output};
 use crate::write;
+use crate::{nix_hash, ValidateDerivationError};
 use serde::{Deserialize, Serialize};
 use sha2::{Digest, Sha256};
 use std::collections::BTreeSet;
 use std::{collections::BTreeMap, fmt, fmt::Write};
 use tvix_store::nixbase32::NIXBASE32;
-use tvix_store::store_path::{ParseStorePathError, StorePath, STORE_DIR};
+use tvix_store::store_path::{StorePath, STORE_DIR};
 
 #[derive(Clone, Debug, Default, Eq, PartialEq, Serialize, Deserialize)]
 pub struct Derivation {
@@ -35,7 +35,7 @@ fn build_store_path(
     is_derivation: bool,
     path_hash: &[u8],
     name: &str,
-) -> Result<StorePath, ParseStorePathError> {
+) -> Result<StorePath, ValidateDerivationError> {
     let compressed = nix_hash::compress_hash(path_hash, 20);
     if is_derivation {
         StorePath::from_string(
@@ -50,6 +50,9 @@ fn build_store_path(
     } else {
         StorePath::from_string(format!("{}-{}", NIXBASE32.encode(&compressed), name,).as_str())
     }
+    .map_err(|_e| ValidateDerivationError::InvalidOutputName(name.to_string()))
+    // Constructing the StorePath can only fail if the passed output name was
+    // invalid, so map errors to a [ValidateDerivationError::InvalidOutputName].
 }
 
 impl Derivation {
@@ -107,7 +110,10 @@ impl Derivation {
     ///   - Take the digest, run hash.CompressHash(digest, 20) on it.
     ///   - Encode it with nixbase32
     ///   - Use it (and the name) to construct a [StorePath].
-    pub fn calculate_derivation_path(&self, name: &str) -> Result<StorePath, ParseStorePathError> {
+    pub fn calculate_derivation_path(
+        &self,
+        name: &str,
+    ) -> Result<StorePath, ValidateDerivationError> {
         let mut hasher = Sha256::new();
 
         // collect the list of paths from input_sources and input_derivations
@@ -224,7 +230,7 @@ impl Derivation {
         &mut self,
         name: &str,
         drv_replacement_str: &str,
-    ) -> Result<(), ParseStorePathError> {
+    ) -> Result<(), ValidateDerivationError> {
         let mut hasher = Sha256::new();
 
         // Check if the Derivation is fixed output, because they cause