`./orbit --init` not working: "Error during WASM file generation for upgrader"

Setup
dfx version: 0.24.0
node version: 20.18.3
Command used to spin up local replica:
dfx start --clean --pocketic --host 127.0.0.1:4943
Command that is not working (executed right after setting up a clean replica):
./orbit --init

Error message

\e[1m$ START:\e[0m setup_control_panel
Current identity: default

**Generating WASM file for upgrader...**
./scripts/generate-wasm.sh: line 16: ${OSTYPE,,}: bad substitution

Full output

➜  orbit git:(main) ./orbit --init
------------------------------------------------------
\e[1m$ START:\e[0m setup_devenv
Loading nvm from /Users/vincxntes/.nvm
Using nvm to manage Node.js versions.
Installing and using Node.js version 20.18...
v20.18.3 is already installed.
Now using node v20.18.3 (npm v10.8.2)
Now using node v20.18.3 (npm v10.8.2)
Node.js is set to the required version using nvm.
Scope: all 5 workspace projects
Lockfile is up to date, resolution step is skipped
Already up to date
. postinstall$ pnpm run -r postinstall && pnpm run prepare…
│ Scope: 4 of 5 workspace projects
│ None of the selected packages has a "postinstall" script
│ > orbit-monorepo@ prepare-cli /Users/vincxntes/orbit
│ > pnpm run --filter orbit-cli build && pnpm run --filter…
│ > orbit-cli@0.0.1 build /Users/vincxntes/orbit/cli
│ > tsc
│ > orbit-cli@0.0.1 expose /Users/vincxntes/orbit/cli
│ > pnpm link --global
└─ Done in 2.2s
Done in 3.1s
\e[1m$ COMPLETED:\e[0m setup_devenv
------------------------------------------------------
\e[1m$ START:\e[0m setup_cmc
Deploying: cmc
cmc canister created with canister id: rkp4c-7iaaa-aaaaa-aaaca-cai
Installed code for canister cmc, with canister ID rkp4c-7iaaa-aaaaa-aaaca-cai
Deployed canisters.
URLs:
  Backend canister via Candid interface:
    cmc: http://127.0.0.1:4943/?canisterId=uqqxf-5h777-77774-qaaaa-cai&id=rkp4c-7iaaa-aaaaa-aaaca-cai
WARN: Cannot fetch Candid interface for set_authorized_subnetwork_list, sending arguments with inferred types.
(null : null)
\e[1m$ COMPLETED:\e[0m setup_cmc
------------------------------------------------------
\e[1m$ START:\e[0m setup_icp_ledger
 *Deploying: icp_ledger
icp_ledger canister created with canister id: ryjl3-tyaaa-aaaaa-aaaba-cai
Installed code for canister icp_ledger, with canister ID ryjl3-tyaaa-aaaaa-aaaba-cai
Deployed canisters.
URLs:
  Backend canister via Candid interface:
    cmc: http://127.0.0.1:4943/?canisterId=uqqxf-5h777-77774-qaaaa-cai&id=rkp4c-7iaaa-aaaaa-aaaca-cai
    icp_ledger: http://127.0.0.1:4943/?canisterId=uqqxf-5h777-77774-qaaaa-cai&id=ryjl3-tyaaa-aaaaa-aaaba-cai
\e[1m$ COMPLETED:\e[0m setup_icp_ledger
------------------------------------------------------
\e[1m$ START:\e[0m setup_icp_index
Deploying: icp_index
icp_index canister created with canister id: qhbym-qaaaa-aaaaa-aaafq-cai
Installed code for canister icp_index, with canister ID qhbym-qaaaa-aaaaa-aaafq-cai
Deployed canisters.
URLs:
  Backend canister via Candid interface:
    cmc: http://127.0.0.1:4943/?canisterId=uqqxf-5h777-77774-qaaaa-cai&id=rkp4c-7iaaa-aaaaa-aaaca-cai
    icp_index: http://127.0.0.1:4943/?canisterId=uqqxf-5h777-77774-qaaaa-cai&id=qhbym-qaaaa-aaaaa-aaafq-cai
    icp_ledger: http://127.0.0.1:4943/?canisterId=uqqxf-5h777-77774-qaaaa-cai&id=ryjl3-tyaaa-aaaaa-aaaba-cai
\e[1m$ COMPLETED:\e[0m setup_icp_index
------------------------------------------------------
\e[1m$ START:\e[0m setup_internet_identity
Deploying: internet_identity
internet_identity canister created with canister id: rdmx6-jaaaa-aaaaa-aaadq-cai
Installed code for canister internet_identity, with canister ID rdmx6-jaaaa-aaaaa-aaadq-cai
Deployed canisters.
URLs:
  Backend canister via Candid interface:
    cmc: http://127.0.0.1:4943/?canisterId=uqqxf-5h777-77774-qaaaa-cai&id=rkp4c-7iaaa-aaaaa-aaaca-cai
    icp_index: http://127.0.0.1:4943/?canisterId=uqqxf-5h777-77774-qaaaa-cai&id=qhbym-qaaaa-aaaaa-aaafq-cai
    icp_ledger: http://127.0.0.1:4943/?canisterId=uqqxf-5h777-77774-qaaaa-cai&id=ryjl3-tyaaa-aaaaa-aaaba-cai
    internet_identity: http://127.0.0.1:4943/?canisterId=uqqxf-5h777-77774-qaaaa-cai&id=rdmx6-jaaaa-aaaaa-aaadq-cai
\e[1m$ COMPLETED:\e[0m setup_internet_identity
------------------------------------------------------
\e[1m$ START:\e[0m setup_control_panel
Current identity: default

Generating WASM file for upgrader...
./scripts/generate-wasm.sh: line 16: ${OSTYPE,,}: bad substitution

Start with scripts/generate-wasm.sh at line 16 and reproduce ./orbit --init using the reported dfx, Node.js, and local replica setup. Confirm that WASM generation completes and the control-panel setup proceeds without the reported bad-substitution error.