diff --git a/.github/workflows/ci_test.yml b/.github/workflows/ci_test.yml
index ecaffb3b..a23b8880 100644
--- a/.github/workflows/ci_test.yml
+++ b/.github/workflows/ci_test.yml
@@ -43,16 +43,16 @@ jobs:
         run: cargo test --locked --test ledger --test ledger_posix_lock --test ledger_lock_aliases --test ledger_retry --test ledger_durability
 
   msrv:
-    name: Rust 1.88 minimum
+    name: Rust 1.90 minimum
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v7
       - uses: dtolnay/rust-toolchain@master
         with:
-          toolchain: 1.88.0
+          toolchain: 1.90.0
       - uses: Swatinem/rust-cache@v2
-      # `time` 0.3.55 (cyclonedx-bom) declares rust-version 1.88.0. Cargo
-      # 1.83 cannot parse the edition2024 manifests those crates ship.
+      # `ordered-float` 5.5.1 declares rust-version 1.90. `uuid` 1.29.0
+      # declares 1.89.0. Cargo 1.89 rejects the lockfile on ordered-float.
       - name: Locked all-targets build
         run: cargo build --locked --all-targets
 
diff --git a/AGENTS.md b/AGENTS.md
index 4122cab2..ac5ddb85 100644
--- a/AGENTS.md
+++ b/AGENTS.md
@@ -96,7 +96,7 @@ only when `EB_STACK_ALLOW_BUILD=1`.
 
 ## Build, test, lint, and docs
 
-Rust 1.88 is the minimum. CI uses current stable. Run builds and tests on
+Rust 1.90 is the minimum. CI uses current stable. Run builds and tests on
 the repository's configured build machine when local compilation is prohibited.
 
 ```sh
diff --git a/CHANGELOG.md b/CHANGELOG.md
index dc8dc256..9390d082 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -2,6 +2,14 @@
 
 All notable changes to this project are documented here.
 
+## Unreleased
+
+### Changed
+
+- Rust 1.90 is the minimum. `ordered-float` 5.5.1 sets `rust-version`
+  1.90. `uuid` 1.29.0 sets 1.89.0. The CI minimum job builds every
+  target with that compiler.
+
 ## 0.4.0 - 2026-11-05
 
 ### Changed
diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
index d40319b2..2a3f6663 100644
--- a/CONTRIBUTING.md
+++ b/CONTRIBUTING.md
@@ -7,7 +7,7 @@ win.
 
 ## Development environment
 
-Rust 1.88 is the minimum supported toolchain; current stable is used for the
+Rust 1.90 is the minimum supported toolchain; current stable is used for the
 main test and lint gates. [pixi](https://pixi.sh) provides docs and optional
 dev tasks:
 
diff --git a/Cargo.toml b/Cargo.toml
index 13357b66..5c510991 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -2,9 +2,9 @@
 name = "eb_stack"
 version = "0.4.0"
 edition = "2021"
-# Floor is 1.88.0: `time` 0.3.55, pulled in by cyclonedx-bom, sets
-# rust-version 1.88.0. Edition 2024 dependencies need Cargo 1.85, below that.
-rust-version = "1.88"
+# Floor is 1.90: `ordered-float` 5.5.1 sets rust-version 1.90.
+# `uuid` 1.29.0 sets 1.89.0. Edition 2024 dependencies need Cargo 1.85.
+rust-version = "1.90"
 description = "Turn conda-forge, Spack, and EasyBuild recipes into Resolvo-solved variants, CycloneDX SBOMs, and build-evaluated package bundles"
 license = "MIT"
 authors = ["Rohit Goswami <rgoswami@ieee.org>"]
diff --git a/README.md b/README.md
index acfbb1cf..c345d466 100644
--- a/README.md
+++ b/README.md
@@ -69,7 +69,7 @@ Report these claims independently:
 ## Install
 
 The crate is `eb_stack` on crates.io; the installed binary is `eb-stack`.
-Rust 1.88 or newer is required when building from source. `rustc` 1.83
+Rust 1.90 or newer is required when building from source. `rustc` 1.83
 stops while reading the crate index: the Cargo feature `edition2024` is
 not stabilized. `rustup toolchain install stable` and `rustup default
 stable` provide a new enough compiler.
diff --git a/docs/orgmode/contributing.org b/docs/orgmode/contributing.org
index 74272d48..58e484a5 100644
--- a/docs/orgmode/contributing.org
+++ b/docs/orgmode/contributing.org
@@ -7,7 +7,7 @@ repo root; keep them aligned when you change either.
 
 * Development environment
 
-Rust 1.88 is the minimum supported toolchain; current stable runs the main test
+Rust 1.90 is the minimum supported toolchain; current stable runs the main test
 and lint gates. Documentation uses [[https://pixi.sh][pixi]]:
 
 #+begin_src bash
diff --git a/docs/orgmode/index.org b/docs/orgmode/index.org
index e8db1035..23d79103 100644
--- a/docs/orgmode/index.org
+++ b/docs/orgmode/index.org
@@ -264,7 +264,7 @@ Build from main for ``stack gap``, ``stack oom``, ``stack from-commit``, ``rebui
 
 * Install
 
-  Rust 1.88 or newer. ~rustc~ 1.83 stops while reading the crate index:
+  Rust 1.90 or newer. ~rustc~ 1.83 stops while reading the crate index:
   the Cargo feature ~edition2024~ is not stabilized. With rustup:
 
 #+begin_src bash
diff --git a/docs/orgmode/reference/mcp.org b/docs/orgmode/reference/mcp.org
index 64798ad3..b4bf848f 100644
--- a/docs/orgmode/reference/mcp.org
+++ b/docs/orgmode/reference/mcp.org
@@ -20,7 +20,7 @@ and the client then runs that binary by name.
 
 * Build the binary
 
-Rust 1.88 or newer builds this tree. The binary that the snippets below
+Rust 1.90 or newer builds this tree. The binary that the snippets below
 call is ~eb-stack~.
 
 #+begin_src bash
diff --git a/llms-full.txt b/llms-full.txt
index 4d77e146..5ddcabe6 100644
--- a/llms-full.txt
+++ b/llms-full.txt
@@ -32,7 +32,7 @@ This file is the manual in one document. The short index is llms.txt.
 
 # Install
 
-  Rust 1.88 or newer. `rustc` 1.83 stops while reading the crate index:
+  Rust 1.90 or newer. `rustc` 1.83 stops while reading the crate index:
   the Cargo feature `edition2024` is not stabilized. With rustup:
 
 ```bash
@@ -8376,7 +8376,7 @@ and the client then runs that binary by name.
 
 # Build the binary
 
-Rust 1.88 or newer builds this tree. The binary that the snippets below
+Rust 1.90 or newer builds this tree. The binary that the snippets below
 call is `eb-stack`.
 
 ```bash
@@ -12515,7 +12515,7 @@ repo root; keep them aligned when you change either.
 
 # Development environment
 
-Rust 1.88 is the minimum supported toolchain; current stable runs the main test
+Rust 1.90 is the minimum supported toolchain; current stable runs the main test
 and lint gates. Documentation uses [pixi](https://pixi.sh):
 
 ```bash
diff --git a/llms.txt b/llms.txt
index 5e8c27b6..7a63547b 100644
--- a/llms.txt
+++ b/llms.txt
@@ -2,7 +2,7 @@
 
 > eb-stack parses conda-forge, Spack, PyPI, CRAN, Cargo, LuaRocks, Raku, and EasyBuild recipes into one package plan, a planned CycloneDX SBOM, Resolvo locks, and conventional EasyBuild recipes.
 
-The binary is `eb-stack`. The crate is `eb_stack`. Rust 1.88 or newer builds it from source. Each link below is the markdown form of a page on https://eb-stack.rgoswami.me/. `llms-full.txt` repeats those pages in one file. Contribution guidelines are in CONTRIBUTING.md. The Model Context Protocol server is `eb-stack mcp`.
+The binary is `eb-stack`. The crate is `eb_stack`. Rust 1.90 or newer builds it from source. Each link below is the markdown form of a page on https://eb-stack.rgoswami.me/. `llms-full.txt` repeats those pages in one file. Contribution guidelines are in CONTRIBUTING.md. The Model Context Protocol server is `eb-stack mcp`.
 
 ## Getting started
 
diff --git a/scripts/gen-llms-txt.py b/scripts/gen-llms-txt.py
index 0ed3147d..9e220f1d 100644
--- a/scripts/gen-llms-txt.py
+++ b/scripts/gen-llms-txt.py
@@ -370,7 +370,7 @@ def render_index(pages: list[dict[str, str]]) -> str:
         + "Raku, and EasyBuild recipes into one package plan, a planned "
         + "CycloneDX SBOM, Resolvo locks, and conventional EasyBuild recipes.",
         "",
-        "The binary is `eb-stack`. The crate is `eb_stack`. Rust 1.88 or "
+        "The binary is `eb-stack`. The crate is `eb_stack`. Rust 1.90 or "
         "newer builds it from source. Each link below is the markdown form "
         "of a page on https://eb-stack.rgoswami.me/. `llms-full.txt` repeats "
         "those pages in one file. Contribution guidelines are in CONTRIBUTING.md. "
diff --git a/tests/public_metadata.rs b/tests/public_metadata.rs
index 1b6b150c..3e9b0cb4 100644
--- a/tests/public_metadata.rs
+++ b/tests/public_metadata.rs
@@ -161,12 +161,12 @@ fn local_agent_state_stays_out_of_public_commits() {
 #[test]
 fn ci_enforces_the_declared_msrv_and_quality_gates() {
     let cargo = std::fs::read_to_string(repo().join("Cargo.toml")).expect("read Cargo.toml");
-    assert!(cargo.contains("rust-version = \"1.88\""));
+    assert!(cargo.contains("rust-version = \"1.90\""));
 
     let ci = std::fs::read_to_string(repo().join(".github/workflows/ci_test.yml"))
         .expect("read test workflow");
     for command in [
-        "toolchain: 1.88.0",
+        "toolchain: 1.90.0",
         "cargo build --locked --all-targets",
         "cargo fmt --all --check",
         "cargo clippy --locked --all-targets -- -D warnings",