diff --git a/shell/ci/env/mise.sh b/shell/ci/env/mise.sh
index 3618e8b1..d5472206 100755
--- a/shell/ci/env/mise.sh
+++ b/shell/ci/env/mise.sh
@@ -35,6 +35,14 @@ inject_mise_commands() {
 # Assumes that `gh` has already been set up.
 ghToken="$(gh auth token)"
 
+# Isolate mise install from global config. Global tools (from orc setup or
+# pre-built CI image in ~/.config/mise/) don't have lockfiles and cause
+# --locked to fail. _MISE_INSTALL_CONFIG_DIR is picked up by run_mise() and
+# applied only to the mise binary invocation, so shims (e.g.
+# wait-for-gh-rate-limit) still resolve against the real global config.
+_MISE_INSTALL_CONFIG_DIR="$(mktemp -d)"
+export _MISE_INSTALL_CONFIG_DIR
+
 # TODO(malept): feature parity with asdf.sh in the same folder.
 if [[ -f "$repoDir"/mise.toml ]]; then
   info_sub "🧑‍🍳 installing tool versions via mise"
@@ -43,10 +51,22 @@ if [[ -f "$repoDir"/mise.toml ]]; then
   else
     info_sub "🧑‍🍳 ignoring .tool-versions (managed by asdf)"
   fi
-  MISE_GITHUB_TOKEN="$ghToken" run_mise install --cd "$repoDir" --yes
+
+  # Use --locked when a lockfile exists to prevent GitHub API calls for
+  # version resolution. Repos without mise.lock fall back to normal install.
+  locked_flag=""
+  if [[ -f "$repoDir"/mise.lock ]]; then
+    locked_flag="--locked"
+  fi
+  # shellcheck disable=SC2086
+  MISE_GITHUB_TOKEN="$ghToken" run_mise install --cd "$repoDir" $locked_flag --yes
 fi
 
 MISE_GITHUB_TOKEN="$ghToken" devbase_install_mise_tools
+
+rm -rf "$_MISE_INSTALL_CONFIG_DIR"
+unset _MISE_INSTALL_CONFIG_DIR
+
 devbase_configure_global_tools
 
 if [[ -n ${BASH_ENV:-} ]]; then
diff --git a/shell/lib/mise.sh b/shell/lib/mise.sh
index 19aa8beb..f17ba15e 100644
--- a/shell/lib/mise.sh
+++ b/shell/lib/mise.sh
@@ -254,8 +254,17 @@ run_mise() {
     tool_versions_override="none"
   fi
 
-  MISE_OVERRIDE_TOOL_VERSIONS_FILENAMES="$tool_versions_override" \
-    "$mise_path" "$@"
+  # _MISE_INSTALL_CONFIG_DIR, when set, overrides MISE_CONFIG_DIR only for
+  # the mise binary — not for helper tools like wait-for-gh-rate-limit
+  # that run via mise shims and need the real global config.
+  if [[ -n ${_MISE_INSTALL_CONFIG_DIR:-} ]]; then
+    MISE_OVERRIDE_TOOL_VERSIONS_FILENAMES="$tool_versions_override" \
+      MISE_CONFIG_DIR="$_MISE_INSTALL_CONFIG_DIR" \
+      "$mise_path" "$@"
+  else
+    MISE_OVERRIDE_TOOL_VERSIONS_FILENAMES="$tool_versions_override" \
+      "$mise_path" "$@"
+  fi
 }
 
 # If `wait-for-gh-rate-limit` is installed, runs it to wait for
@@ -417,7 +426,20 @@ devbase_install_mise_tools() {
   if ! mise_version_compatible "2025.10.11"; then
     mise settings set experimental true
   fi
-  devbase_mise install --yes
+  # go: backend tools compile from source and can't produce lockfile URLs,
+  # so --locked always fails for them (mise bug: go backend doesn't override
+  # supports_lockfile_url). MISE_DISABLE_BACKENDS=go also doesn't work for
+  # explicitly declared tools (mise bug: get() bypasses the filter).
+  # Workaround: use MISE_DISABLE_TOOLS with the actual go: tool names.
+  local devbaseDir
+  devbaseDir="$(get_devbase_directory)"
+  local go_tools
+  go_tools=$(grep '^"go:' "$devbaseDir/mise.devbase.toml" | cut -d'"' -f2 | paste -sd, -)
+  # Pass 1: all lockable tools with --locked (no GitHub API calls)
+  MISE_DISABLE_TOOLS="$go_tools" devbase_mise install --yes --locked
+  # Pass 2: go: tools without --locked (they use Go module proxy, not GitHub API).
+  # MISE_LOCKFILE=false prevents lockfile writes — CI must never mutate lockfiles.
+  MISE_LOCKFILE=false devbase_mise install --yes
 }
 
 # The current version of mise.