sopherapps · ch-ahindura · Aug 7, 2026 · Aug 7, 2026 · Aug 7, 2026
diff --git a/CHANGELOG.md b/CHANGELOG.md
@@ -7,6 +7,14 @@ and this project follows versions of format `{year}.{month}.{patch_number}`.
 
 ## [Unreleased]
 
+## [0.4.1] - 2026-08-07
+
+### Fixed
+
+- `qpi-driver/py`: a `quantify` tuner or executor creates its data directory's parents.
+  quantify-core's own `mkdir` is not recursive, so `bin/data` in a fresh checkout
+  failed at construction.
+
 ## [0.4.0] - 2026-08-06
 
 ### Added

diff --git a/Makefile b/Makefile
@@ -1,6 +1,6 @@
 .PHONY: test-dashboard test-docs test-docs-static test-docs-snippets test-docs-example test-docs-site all build build-dashboard test test-js-driver test-go-driver lint lint-go lint-py lint-js lint-dashboard lint-go-client lint-py-client lint-js-driver lint-go-driver format format-go format-py format-js format-dashboard format-go-client format-py-client format-js-driver format-go-driver package package-driver package-driver-js package-driver-go package-js package-py package-go publish-js publish-driver-js publish-py clean venv-check test-e2e-dashboard
 
-VERSION ?= 0.4.0
+VERSION ?= 0.4.1
 UV := $(shell command -v uv 2> /dev/null || echo "$$HOME/.local/bin/uv")
 
 # Scratch locations for the documentation checks. Under bin/, which is already

diff --git a/README.md b/README.md
@@ -77,12 +77,12 @@ The server is available as a single executable binary, as well as native OS pack
 #### Standalone Binary (macOS & Linux)
 Download the binary for your platform, make it executable, and run:
 ```bash
-# macOS (replace 0.4.0 with the version you wish to install)
-curl -LO https://github.com/sopherapps/qpi/releases/download/v0.4.0/qpi-0.4.0-darwin-amd64
-chmod +x qpi-0.4.0-darwin-amd64 && mv qpi-0.4.0-darwin-amd64 qpi
+# macOS (replace 0.4.1 with the version you wish to install)
+curl -LO https://github.com/sopherapps/qpi/releases/download/v0.4.1/qpi-0.4.1-darwin-amd64
+chmod +x qpi-0.4.1-darwin-amd64 && mv qpi-0.4.1-darwin-amd64 qpi
 
 # Linux (standalone binary)
-curl -L https://github.com/sopherapps/qpi/releases/download/v0.4.0/qpi-0.4.0-linux-amd64.tar.gz | tar -xz
+curl -L https://github.com/sopherapps/qpi/releases/download/v0.4.1/qpi-0.4.1-linux-amd64.tar.gz | tar -xz
 
 # Start the server
 ./qpi serve
@@ -91,8 +91,8 @@ curl -L https://github.com/sopherapps/qpi/releases/download/v0.4.0/qpi-0.4.0-lin
 #### Native Linux Packages (Ubuntu, Debian, Fedora, Alpine)
 For Debian/Ubuntu, download and install the `.deb` package:
 ```bash
-wget https://github.com/sopherapps/qpi/releases/download/v0.4.0/qpi_0.4.0_amd64.deb
-sudo apt install ./qpi_0.4.0_amd64.deb
+wget https://github.com/sopherapps/qpi/releases/download/v0.4.1/qpi_0.4.1_amd64.deb
+sudo apt install ./qpi_0.4.1_amd64.deb
 ```
 *(Note: Installing the package automatically registers and starts `qpi.service` under systemd (or OpenRC on Alpine) to run the server in the background on port `8090`)*
 

diff --git a/qpi-client/js/package-lock.json b/qpi-client/js/package-lock.json
diff --git a/qpi-client/js/package.json b/qpi-client/js/package.json
@@ -1,6 +1,6 @@
 {
   "name": "qpi-client",
-  "version": "0.4.0",
+  "version": "0.4.1",
   "description": "JavaScript/TypeScript client SDK for the QPI quantum computing platform",
   "main": "dist/index.js",
   "types": "dist/index.d.ts",

diff --git a/qpi-client/py/pyproject.toml b/qpi-client/py/pyproject.toml
@@ -4,7 +4,7 @@ build-backend = "setuptools.build_meta"
 
 [project]
 name = "qpi-client"
-version = "0.4.0"
+version = "0.4.1"
 description = "Python client SDK for the QPI quantum computing platform"
 readme = "README.md"
 license = {text = "MIT"}

diff --git a/qpi-client/py/qpi_client/__init__.py b/qpi-client/py/qpi_client/__init__.py
@@ -30,7 +30,7 @@
 try:
     __version__ = importlib.metadata.version("qpi-client")
 except importlib.metadata.PackageNotFoundError:
-    __version__ = "0.4.0"
+    __version__ = "0.4.1"
 
 from qpi_client.client import QPIClient
 from qpi_client.provider import QPIBackend, QPIJob

diff --git a/qpi-client/py/uv.lock b/qpi-client/py/uv.lock
diff --git a/qpi-driver/go/cli/cli.go b/qpi-driver/go/cli/cli.go
@@ -27,7 +27,7 @@ import (
 
 // Version is the CLI version; overridable at build time with
 // -ldflags "-X github.com/sopherapps/qpi/qpi-driver/go/cli.Version=…".
-var Version = "0.4.0"
+var Version = "0.4.1"
 
 // commonFlags are the universal options `start` shares across every operation,
 // mirroring the Python CLI. A device's own settings go through -o instead.

diff --git a/qpi-driver/js/package-lock.json b/qpi-driver/js/package-lock.json
diff --git a/qpi-driver/js/package.json b/qpi-driver/js/package.json
@@ -1,6 +1,6 @@
 {
   "name": "qpi-driver",
-  "version": "0.4.0",
+  "version": "0.4.1",
   "description": "TypeScript/JavaScript SDK for building QPI quantum platform drivers",
   "main": "dist/index.js",
   "types": "dist/index.d.ts",

diff --git a/qpi-driver/py/pyproject.toml b/qpi-driver/py/pyproject.toml
@@ -4,7 +4,7 @@ build-backend = "setuptools.build_meta"
 
 [project]
 name = "qpi-driver"
-version = "0.4.0"
+version = "0.4.1"
 description = "Quantum Processing Interface (QPI) QPU Driver"
 readme = "README.md"
 requires-python = ">=3.12,<3.13"

diff --git a/qpi-driver/py/qpi_driver/__init__.py b/qpi-driver/py/qpi_driver/__init__.py
@@ -3,7 +3,7 @@
 try:
     __version__ = importlib.metadata.version("qpi-driver")
 except importlib.metadata.PackageNotFoundError:
-    __version__ = "0.4.0"
+    __version__ = "0.4.1"
 
 from qpi_driver.builtins import (
     DeviceBuilder,

diff --git a/qpi-driver/py/qpi_driver/cli.py b/qpi-driver/py/qpi_driver/cli.py
@@ -253,7 +253,7 @@ def _get_version() -> str:
         try:
             return importlib.metadata.version("qpi-driver")
         except importlib.metadata.PackageNotFoundError:
-            return "0.4.0"
+            return "0.4.1"
 
     def _banner():
         """Renders the banner at the top of the CLI"""

diff --git a/qpi-driver/py/qpi_driver/compat/quantify.py b/qpi-driver/py/qpi_driver/compat/quantify.py
@@ -2,6 +2,7 @@
 
 import logging
 from enum import Enum
+from pathlib import Path
 from typing import Any, TypeAlias
 
 from qpi_driver.compat.shared import BasicCompatClass
@@ -14,7 +15,7 @@
     from qcodes.instrument.channel import InstrumentChannel
     from qcodes.instrument.parameter import ManualParameter
     from qcodes.parameters import ParameterBase
-    from quantify_core.data.handling import set_datadir
+    from quantify_core.data.handling import set_datadir as _set_datadir
     from quantify_scheduler import Operation, Schedule
     from quantify_scheduler.backends.graph_compilation import SerialCompiler
     from quantify_scheduler.backends.qblox_backend import (
@@ -69,7 +70,7 @@
     logging.debug(f"failed importing from quantify.compat {exp}")
     IS_QUANTIFY_INSTALLED: bool = False
 
-    def set_datadir(*args, **kwargs):
+    def _set_datadir(*args, **kwargs):
         pass
 
     def field_validator(*args, **kwargs):
@@ -168,3 +169,17 @@ class Instrument(BasicCompatClass):
         @classmethod
         def close_all(cls):
             pass
+
+
+def set_datadir(datadir: Any = None) -> None:
+    """quantify-core's ``set_datadir``, with the directory created first.
+
+    Its own ``mkdir`` is not recursive, so pointing it anywhere whose *parent* does
+    not exist yet dies with a ``FileNotFoundError`` naming the child — `bin/data` in
+    a checkout where nothing has run `make build`, or a service's data directory
+    before its first start. The path is already vetted as safe by
+    :func:`~qpi_driver.paths.as_safe_dir` wherever it came from an ``-o`` option.
+    """
+    if datadir is not None:
+        Path(datadir).mkdir(parents=True, exist_ok=True)
+    _set_datadir(datadir)
diff --git a/qpi-driver/py/tests/test_cli.py b/qpi-driver/py/tests/test_cli.py
@@ -40,7 +40,7 @@ def test_cli_version():
     try:
         expected_version = importlib.metadata.version("qpi-driver")
     except importlib.metadata.PackageNotFoundError:
-        expected_version = "0.4.0"
+        expected_version = "0.4.1"
     assert expected_version in result.stdout
 
 
@@ -418,7 +418,7 @@ def test_version_falls_back_when_the_package_is_not_installed():
         "version",
         side_effect=importlib.metadata.PackageNotFoundError("qpi-driver"),
     ):
-        assert _get_version() == "0.4.0"
+        assert _get_version() == "0.4.1"
 
 
 def test_cli_process_requires_token():

diff --git a/qpi-driver/py/uv.lock b/qpi-driver/py/uv.lock
diff --git a/qpi-ui/internal/dashboard/package-lock.json b/qpi-ui/internal/dashboard/package-lock.json
diff --git a/qpi-ui/internal/dashboard/package.json b/qpi-ui/internal/dashboard/package.json
@@ -1,7 +1,7 @@
 {
   "name": "dashboard-src",
   "private": true,
-  "version": "0.4.0",
+  "version": "0.4.1",
   "type": "module",
   "scripts": {
     "dev": "vite",

diff --git a/qpi-ui/main.go b/qpi-ui/main.go
@@ -20,7 +20,7 @@ import (
 //go:embed all:internal/dashboard/dist
 var dashboardFS embed.FS
 
-var Version = "v0.4.0"
+var Version = "v0.4.1"
 
 func main() {
 	app := pocketbase.New()

diff --git a/qpi-ui/pkg/qpi.wxs b/qpi-ui/pkg/qpi.wxs
@@ -1,6 +1,6 @@
 <?xml version="1.0" encoding="utf-8"?>
 <Wix xmlns="http://schemas.microsoft.com/wix/2006/wi">
-  <Product Name="QPI Server" Id="*" UpgradeCode="32AAA554-16F5-420B-B646-6A57FF07D1B0" Language="1033" Codepage="1252" Version="0.4.0" Manufacturer="SopherApps">
+  <Product Name="QPI Server" Id="*" UpgradeCode="32AAA554-16F5-420B-B646-6A57FF07D1B0" Language="1033" Codepage="1252" Version="0.4.1" Manufacturer="SopherApps">
     <Package InstallScope="perMachine" Id="*" Keywords="Installer" Description="QPI Server Installer" Compressed="yes" />
     <Media Id="1" Cabinet="qpi.cab" EmbedCab="yes" />