diff --git a/clingo/spec_info.json b/clingo/spec_info.json
deleted file mode 100644
index ec49bae..0000000
--- a/clingo/spec_info.json
+++ /dev/null
@@ -1,7 +0,0 @@
-{
-    "centos7-x86_64": "clingo-bootstrap%gcc platform=linux target=x86_64",
-    "centos7-aarch64": "clingo-bootstrap%gcc platform=linux target=aarch64",
-    "centos7-ppc64le": "clingo-bootstrap%gcc platform=linux target=ppc64le",
-    "highsierra-x86_64": "clingo-bootstrap%apple-clang platform=darwin target=x86_64",
-    "bigsur-aarch64": "clingo-bootstrap%apple-clang platform=darwin target=aarch64"
-}
\ No newline at end of file
diff --git a/generate_bootstrap_json.py b/generate_bootstrap_json.py
index 6b1cf11..e804603 100755
--- a/generate_bootstrap_json.py
+++ b/generate_bootstrap_json.py
@@ -16,9 +16,6 @@
 #
 # "spec": root spec to be matched
 # "binaries": list of tuples (pkg name, dag hash, sha256 sum)
-# optionally "python": constraints on the python interpreter (could've been part of `spec` but
-# for unknown reasons it is not)
-
 
 def sha256(path):
     fn = hashlib.sha256()
@@ -33,7 +30,7 @@ def tarball_hash(path: str):
     return name.split("-")[-1]
 
 
-def run(pkg: str, arch_to_spec: Dict[str, str], deps=dt.NONE, python: bool = False):
+def run(pkg: str, deps=dt.NONE, python: bool = False):
     name = "clingo-bootstrap" if pkg == "clingo" else pkg
     shas = {
         tarball_hash(tarball): sha256(tarball)
@@ -46,15 +43,16 @@ def run(pkg: str, arch_to_spec: Dict[str, str], deps=dt.NONE, python: bool = Fal
 
     assert len(specs) > 0, f"No specs found for {name}"
 
+    fmt = "{name}{@version}{%compiler.name} platform={platform} target={target}"
+
     if python:
-        with_python = lambda s: {"python": f"python@{s.dependencies('python')[0].version}"}
+        fmt_spec = lambda s: f"{s.format(fmt)} ^python@{s.dependencies('python')[0].version}"
     else:
-        with_python = lambda _: {}
+        fmt_spec = lambda s: s.format(fmt)
 
     mirror_info = [
         {
-            "spec": arch_to_spec[f"{s.architecture.os}-{s.architecture.target}"],
-            **with_python(s),
+            "spec": fmt_spec(s),
             "binaries": [
                 (s.name, s.dag_hash(), shas[s.dag_hash()])
                 for s in reversed(list(s.traverse(order="topo", deptype=deps)))
@@ -64,8 +62,8 @@ def run(pkg: str, arch_to_spec: Dict[str, str], deps=dt.NONE, python: bool = Fal
         for s in specs
     ]
 
-    if python:
-        mirror_info.sort(key=lambda x: spack.spec.Spec(x["python"]))
+    # sort as strings, cause Spec instances with deps don't sort properly
+    mirror_info.sort(key=lambda x: x["spec"])
 
     with open(f"./{pkg}.json", "w") as f:
         json.dump({"verified": mirror_info}, f, sort_keys=True, indent=2)
@@ -76,10 +74,8 @@ def run(pkg: str, arch_to_spec: Dict[str, str], deps=dt.NONE, python: bool = Fal
     pkg = sys.argv[1]
     # unfortunately we refer to clingo-bootstrap by alias "clingo"
     assert pkg in ("clingo", "gnupg", "patchelf")
-    file = f"{os.path.dirname(__file__)}/{pkg}/spec_info.json"
     run(
         pkg,
-        arch_to_spec=json.load(open(file)),
         # clingo is special: statically links libstdc++ and other deps are loaded by interpreter
         deps=dt.NONE if pkg == "clingo" else dt.LINK | dt.RUN,
         python=pkg == "clingo",
diff --git a/gnupg/spec_info.json b/gnupg/spec_info.json
deleted file mode 100644
index df34129..0000000
--- a/gnupg/spec_info.json
+++ /dev/null
@@ -1,7 +0,0 @@
-{
-    "centos7-x86_64": "gnupg@2.3: %gcc platform=linux target=x86_64",
-    "centos7-aarch64": "gnupg@2.3: %gcc platform=linux target=aarch64",
-    "centos7-ppc64le": "gnupg@2.3: %gcc platform=linux target=ppc64le",
-    "highsierra-x86_64": "gnupg@2.3: %apple-clang platform=darwin target=x86_64",
-    "bigsur-aarch64": "gnupg@2.3: %apple-clang platform=darwin target=aarch64"
-}
\ No newline at end of file
diff --git a/patchelf/spec_info.json b/patchelf/spec_info.json
deleted file mode 100644
index 1feb61b..0000000
--- a/patchelf/spec_info.json
+++ /dev/null
@@ -1,5 +0,0 @@
-{
-    "centos7-x86_64": "patchelf@0.13: %gcc platform=linux target=x86_64",
-    "centos7-aarch64": "patchelf@0.13: %gcc platform=linux target=aarch64",
-    "centos7-ppc64le": "patchelf@0.13: %gcc platform=linux target=ppc64le"
-}
\ No newline at end of file