In reply to @jade_:matrix.org
was i working on a new one? i don't remember having done so

This is correct however:

#if __linux__
                /* If we are using no sandboxing, we still need to use the physical prefix. */
                useChroot ? logicalTargetPath : prefix + logicalTargetPath;
#else
                prefix + logicalTargetPath;
#endif

I think this patch works for me:

diff --git a/lix/libstore/build/local-derivation-goal.cc b/lix/libstore/build/local-derivation-goal.cc
index e0e14b09f..33f46dc93 100644
--- a/lix/libstore/build/local-derivation-goal.cc
+++ b/lix/libstore/build/local-derivation-goal.cc
@@ -918,7 +918,11 @@ void LocalDerivationGoal::setupConfiguredCertificateAuthority()
 {
     if (settings.caFile != "") {
         if (pathAccessible(settings.caFile)) {
+#if __linux__
             auto prefix = useChroot ? chrootRootDir : tmpDir;
+#else
+            auto prefix = tmpDir;
+#endif
             debug(
                 "rendering visible configured CA '%s' in the builder (prefix directory: '%s')",
                 settings.caFile,
@@ -1249,8 +1253,6 @@ void LocalDerivationGoal::runChild()
                         "non-functional."
                     );
                 }
-
-                setupConfiguredCertificateAuthority();
             }
 
             for (auto & i : ss) pathsInChroot.emplace(i, i);
@@ -1406,11 +1408,8 @@ void LocalDerivationGoal::runChild()
         }
 #endif
 
-        if (!useChroot) {
-            /* When chroot is not used, FODs still requires a CA to be available as well. */
-            if (!derivationType->isSandboxed()) {
-                setupConfiguredCertificateAuthority();
-            }
+        if (!derivationType->isSandboxed()) {
+            setupConfiguredCertificateAuthority();
         }
 
         if (chdir(tmpDirInSandbox.c_str()) == -1)

Run-time dependency rnix-0.12-rs found: NO (tried pkgconfig, framework and cmake)
Looking for a fallback subproject for the dependency rnix-0.12-rs

Executing subproject rnix-0.12-rs method cargo 

lix/lix-doc/meson.build:1: WARNING: Cargo subproject is an experimental feature and has no backwards compatibility guarantees.
rnix-0.12-rs| WARNING: Binary entry all-packages has unexpected keys "path". This may (unlikely) be an error in the cargo manifest, or may be a missing implementation in Meson. If this issue can be reproduced with the latest version of Meson, please help us by opening an issue at https://github.com/mesonbuild/meson/issues. Please include the crate and version that is generating this warning if possible.
rnix-0.12-rs| WARNING: Binary entry dump-ast has unexpected keys "path". This may (unlikely) be an error in the cargo manifest, or may be a missing implementation in Meson. If this issue can be reproduced with the latest version of Meson, please help us by opening an issue at https://github.com/mesonbuild/meson/issues. Please include the crate and version that is generating this warning if possible.
rnix-0.12-rs| WARNING: Binary entry error-report has unexpected keys "path". This may (unlikely) be an error in the cargo manifest, or may be a missing implementation in Meson. If this issue can be reproduced with the latest version of Meson, please help us by opening an issue at https://github.com/mesonbuild/meson/issues. Please include the crate and version that is generating this warning if possible.
rnix-0.12-rs| WARNING: Binary entry from-stdin has unexpected keys "path". This may (unlikely) be an error in the cargo manifest, or may be a missing implementation in Meson. If this issue can be reproduced with the latest version of Meson, please help us by opening an issue at https://github.com/mesonbuild/meson/issues. Please include the crate and version that is generating this warning if possible.
rnix-0.12-rs| WARNING: Binary entry list-fns has unexpected keys "path". This may (unlikely) be an error in the cargo manifest, or may be a missing implementation in Meson. If this issue can be reproduced with the latest version of Meson, please help us by opening an issue at https://github.com/mesonbuild/meson/issues. Please include the crate and version that is generating this warning if possible.
rnix-0.12-rs| WARNING: Binary entry preserve has unexpected keys "path". This may (unlikely) be an error in the cargo manifest, or may be a missing implementation in Meson. If this issue can be reproduced with the latest version of Meson, please help us by opening an issue at https://github.com/mesonbuild/meson/issues. Please include the crate and version that is generating this warning if possible.
rnix-0.12-rs| WARNING: Binary entry test-nixpkgs has unexpected keys "path". This may (unlikely) be an error in the cargo manifest, or may be a missing implementation in Meson. If this issue can be reproduced with the latest version of Meson, please help us by opening an issue at https://github.com/mesonbuild/meson/issues. Please include the crate and version that is generating this warning if possible.
rnix-0.12-rs| WARNING: Binary entry tidy has unexpected keys "path". This may (unlikely) be an error in the cargo manifest, or may be a missing implementation in Meson. If this issue can be reproduced with the latest version of Meson, please help us by opening an issue at https://github.com/mesonbuild/meson/issues. Please include the crate and version that is generating this warning if possible.
rnix-0.12-rs| WARNING: Binary entry math has unexpected keys "path". This may (unlikely) be an error in the cargo manifest, or may be a missing implementation in Meson. If this issue can be reproduced with the latest version of Meson, please help us by opening an issue at https://github.com/mesonbuild/meson/issues. Please include the crate and version that is generating this warning if possible.
rnix-0.12-rs| WARNING: Binary entry s_expressions has unexpected keys "path". This may (unlikely) be an error in the cargo manifest, or may be a missing implementation in Meson. If this issue can be reproduced with the latest version of Meson, please help us by opening an issue at https://github.com/mesonbuild/meson/issues. Please include the crate and version that is generating this warning if possible.

lix/lix-doc/meson.build:1:7: ERROR: Subproject exists but has no Cargo.toml file.