Bundle our own R 4.5.3 instead of building against Arch's R

Arch ships R 4.6.1, but JASP pins its R packages against a frozen CRAN
snapshot (2026-03-31 for 0.98.1) that targets R 4.5. Configuring against
Arch's R fails at Rcpp 1.1.1, which cannot compile on R 4.6 since
R_NamespaceRegistry was removed; the Rcpp release that fixes it is newer
than the pinned snapshot, so the lockfile cannot reach it either.

Build R 4.5.3 into /opt/jasp-desktop/R and point R_HOME at it, matching
what upstream CI does. This drops 'r' from depends entirely, so an Arch R
upgrade can no longer break an installed JASP, and the rebuild triggers
become Qt6 and ICU - the libraries actually still linked against.

scripts/check-upstream.py

@@ -1,9 +1,10 @@
 #!/usr/bin/env python3
 """Decide whether a rebuild is needed.
 
-A JASP binary is only valid for the R minor and Qt6 minor it was linked against,
-so a rebuild is triggered by an upstream JASP release *or* by Arch moving R or
-Qt6 — not just the former.
+The build bundles its own R, so Arch's `r` is irrelevant here. What the binary
+*is* still linked against is Qt6 and ICU, both of which break ABI across
+releases — so a rebuild is triggered by an upstream JASP release or by Arch
+moving either of those.
 
 Writes GITHUB_OUTPUT-style key=value pairs to stdout (and to $GITHUB_OUTPUT).
 """
@@ -40,8 +41,8 @@ def main() -> int:
     pinned_tag = os.environ.get("JASP_TAG", "").strip()
 
     jasp_tag = pinned_tag or fetch_json(GH_LATEST)["tag_name"]
-    r_minor = minor(arch_version("r"))
     qt_minor = minor(arch_version("qt6-base"))
+    icu_major = arch_version("icu").split(".")[0]
 
     try:
         state = json.loads(open(STATE_FILE).read())
@@ -53,16 +54,16 @@ def main() -> int:
         reasons.append("manually forced")
     if state.get("jasp_tag") != jasp_tag:
         reasons.append(f"JASP {state.get('jasp_tag', 'none')} -> {jasp_tag}")
-    if state.get("r_minor") != r_minor:
-        reasons.append(f"R {state.get('r_minor', 'none')} -> {r_minor}")
     if state.get("qt6_minor") != qt_minor:
         reasons.append(f"Qt6 {state.get('qt6_minor', 'none')} -> {qt_minor}")
+    if state.get("icu_major") != icu_major:
+        reasons.append(f"ICU {state.get('icu_major', 'none')} -> {icu_major}")
 
     needs_build = bool(reasons)
 
     print(f"jasp_tag  = {jasp_tag}")
-    print(f"r_minor   = {r_minor}")
     print(f"qt6_minor = {qt_minor}")
+    print(f"icu_major = {icu_major}")
     print(f"decision  = {'BUILD' if needs_build else 'up to date'}")
     for reason in reasons:
         print(f"  reason: {reason}")
@@ -72,8 +73,8 @@ def main() -> int:
         with open(out, "a") as fh:
             fh.write(f"needs_build={'true' if needs_build else 'false'}\n")
             fh.write(f"jasp_tag={jasp_tag}\n")
-            fh.write(f"r_minor={r_minor}\n")
             fh.write(f"qt6_minor={qt_minor}\n")
+            fh.write(f"icu_major={icu_major}\n")
             fh.write(f"reasons={'; '.join(reasons)}\n")
     return 0
 

scripts/gen-pkgbuild.py

@@ -63,17 +63,18 @@ def main() -> int:
         f"/releases/download/{tag}/{info['tarball']}"
     )
 
-    r_minor = info["r_minor"]
     qt_minor = info["qt6_minor"]
+    icu_major = info["icu_major"]
 
     substitutions = {
         "@MAINTAINER@": args.maintainer,
         "@JASP_VERSION@": jasp_version,
         "@PKGREL@": str(pkgrel),
-        "@R_MINOR@": r_minor,
-        "@R_NEXT_MINOR@": next_minor(r_minor),
+        "@BUNDLED_R@": info["bundled_r_version"],
         "@QT_MINOR@": qt_minor,
         "@QT_NEXT_MINOR@": next_minor(qt_minor),
+        "@ICU_MAJOR@": icu_major,
+        "@ICU_NEXT_MAJOR@": str(int(icu_major) + 1),
         "@DOWNLOAD_URL@": download_url,
         "@SHA256@": info["sha256"],
     }
@@ -95,8 +96,9 @@ def main() -> int:
         json.dump({"tag": tag, "pkgrel": pkgrel, "download_url": download_url, **info}, fh, indent=2)
 
     print(f"wrote {args.out} ({args.pkgname} {jasp_version}-{pkgrel})")
-    print(f"  R  pinned to >={r_minor} <{next_minor(r_minor)}")
-    print(f"  Qt pinned to >={qt_minor} <{next_minor(qt_minor)}")
+    print(f"  R   bundled at {info['bundled_r_version']} (not an Arch dependency)")
+    print(f"  Qt  pinned to >={qt_minor} <{next_minor(qt_minor)}")
+    print(f"  ICU pinned to >={icu_major} <{int(icu_major) + 1}")
     return 0
 
 

scripts/record-state.sh

@@ -16,8 +16,9 @@ state = {
     "jasp_tag": meta["jasp_tag"],
     "jasp_version": meta["jasp_version"],
     "pkgrel": meta["pkgrel"],
-    "r_minor": meta["r_minor"],
+    "bundled_r_version": meta["bundled_r_version"],
     "qt6_minor": meta["qt6_minor"],
+    "icu_major": meta["icu_major"],
     "sha256": meta["sha256"],
     "download_url": meta["download_url"],
 }