ci: add JERBOA_CC_OPT=-O0 (OOM fix) and mkdir -p ~/.cache

ober

f63bea08f6618f1ec78d229e5466be5b37a3779e

diff --git a/.build.yml b/.build.yml
index 79272d4..12f9bd9 100644
--- a/.build.yml
+++ b/.build.yml
@@ -20,7 +20,7 @@ tasks:
       curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | \
         sh -s -- -y --profile minimal --default-toolchain 1.94.1
       source "$HOME/.cargo/env"
-      make jerboa CHEZ_CONFIGURE_EXTRA=--disable-x11 JERBOA_NATIVE_FEATURES=tls
+      make jerboa CHEZ_CONFIGURE_EXTRA=--disable-x11 JERBOA_NATIVE_FEATURES=tls JERBOA_CC_OPT=-O0
       echo 'export PATH="$HOME/jerboa/dist:$PATH"' >> ~/.buildenv
   - test-shell: |
       cd jerboa-shell
@@ -28,7 +28,7 @@ tasks:
   - package: |
       cd jerboa-shell
       J="$HOME/jerboa/dist/jerboa"
-      chmod -R go-w "$HOME/.cache"
+      mkdir -p "$HOME/.cache" && chmod -R go-w "$HOME/.cache"
       "$J" pkg verify
       "$J" pkg policy
       "$J" pkg build