these things probably have the same cause, i think - the build can have paths gc'd from under them

       > checking for riscv64-unknown-linux-gnu-gcc... riscv64-unknown-linux-gnu-gcc
       > checking whether the C compiler works... no
       > configure: error: in '/build/hello-2.12.3':
       > configure: error: C compiler cannot create executables
       > See 'config.log' for more details

terminating due to unexpected unrecoverable internal error: Assertion 'false' failed in nix::DerivationTrampolineGoal::init()::<lambda()> at ../src/libstore/build/derivation-trampoline-goal.cc:125

this one is probably the fetcher thing?

       … while calling the 'import' builtin
         at /home/dram/code/config/flake.nix:53:24:
           52|     flake-utils.lib.eachDefaultSystem (system: {
           53|       legacyPackages = import nixpkgs {
             |                        ^
           54|         inherit system;

       (stack trace truncated; use '--show-trace' to show the full, detailed trace)

       error: path '/nix/store/yxn9vm8hjp9j9vkn1979bh9rzg2gga94-source' is not valid

here's another error from the gc process

finding garbage collector roots...
deleting garbage...
deleting '/nix/store/tmp-942181-1014327575'
1 store paths deleted, 0.0 KiB freed
error:
       … While deleting garbage in store directory "/home/dram/tmp/teststore/nix/store/tmp-942181-1014327575"

       error: opening directory "/home/dram/tmp/teststore/nix/store/tmp-942181-1014327575/x/pkgs/by-name/an/anime4k": No such file or directory

But:

#0  std::_List_iterator<std::pair<std::shared_ptr<boost::re_detail_500::cpp_regex_traits_implementation<char> const>, boost::re_detail_500::cpp_regex_traits_base<char> const*> >::operator++ (this=<optimized out>)
    at /nix/store/yps9cjmi8g58mh0f7pw902br7gxwg2dz-gcc-14.3.0/include/c++/14.3.0/bits/stl_list.h:290
#1  std::__cxx11::list<std::pair<std::shared_ptr<boost::re_detail_500::cpp_regex_traits_implementation<char> const>, boost::re_detail_500::cpp_regex_traits_base<char> const*>, std::allocator<std::pair<std::shared_ptr<boost::re_detail_500::cpp_regex_traits_implementation<char> const>, boost::re_detail_500::cpp_regex_traits_base<char> const*> > >::splice (this=0x7ff093ffcc00, __position={...},
    __i=<error reading variable: Cannot access memory at address 0x50>, __x=...)
    at /nix/store/yps9cjmi8g58mh0f7pw902br7gxwg2dz-gcc-14.3.0/include/c++/14.3.0/bits/stl_list.h:1672
#2  std::__cxx11::list<std::pair<std::shared_ptr<boost::re_detail_500::cpp_regex_traits_implementation<char> const>, boost::re_detail_500::cpp_regex_traits_base<char> const*>, std::allocator<std::pair<std::shared_ptr<boost::re_detail_500::cpp_regex_traits_implementation<char> const>, boost::re_detail_500::cpp_regex_traits_base<char> const*> > >::splice (this=0x7ff093ffcc00, __position={...},
    __i=<error reading variable: Cannot access memory at address 0x50>, __x=...)
    at /nix/store/yps9cjmi8g58mh0f7pw902br7gxwg2dz-gcc-14.3.0/include/c++/14.3.0/bits/stl_list.h:1699
#3  boost::object_cache<boost::re_detail_500::cpp_regex_traits_base<char>, boost::re_detail_500::cpp_regex_traits_implementation<char> >::do_get (k=..., l_max_cache_size=l_max_cache_size@entry=5)
    at /nix/store/zw6w6chqvqsh2c6jfsb4pw9bpgdkmjnh-boost-1.87.0-dev/include/boost/regex/v5/object_cache.hpp:100
#4  0x00007ff4bd772e95 in boost::object_cache<boost::re_detail_500::cpp_regex_traits_base<char>, boost::re_detail_500::cpp_regex_traits_implementation<char> >::get (k=..., l_max_cache_size=5)
    at /nix/store/zw6w6chqvqsh2c6jfsb4pw9bpgdkmjnh-boost-1.87.0-dev/include/boost/regex/v5/object_cache.hpp:70
#5  boost::re_detail_500::create_cpp_regex_traits<char> (l=Python Exception <class 'gdb.error'>: There is no member named _M_impl.
)
    at /nix/store/zw6w6chqvqsh2c6jfsb4pw9bpgdkmjnh-boost-1.87.0-dev/include/boost/regex/v5/cpp_regex_traits.hpp:729
#6  0x00007ff4bd772d7f in boost::cpp_regex_traits<char>::cpp_regex_traits (this=0x7ff08c009ef0)
    at /nix/store/zw6w6chqvqsh2c6jfsb4pw9bpgdkmjnh-boost-1.87.0-dev/include/boost/regex/v5/cpp_regex_traits.hpp:749
#7  boost::regex_traits<char, boost::cpp_regex_traits<char> >::regex_traits (this=0x7ff08c009ef0)
    at /nix/store/zw6w6chqvqsh2c6jfsb4pw9bpgdkmjnh-boost-1.87.0-dev/include/boost/regex/v5/regex_traits.hpp:39
#8  boost::regex_traits_wrapper<boost::regex_traits<char, boost::cpp_regex_traits<char> > >::regex_traits_wrapper (this=0x7ff08c009ef0)
    at /nix/store/zw6w6chqvqsh2c6jfsb4pw9bpgdkmjnh-boost-1.87.0-dev/include/boost/regex/v5/regex_traits.hpp:121
#9  boost::re_detail_500::regex_data<char, boost::regex_traits<char, boost::cpp_regex_traits<char> > >::regex_data (this=0x7ff08c009d50)
    at /nix/store/zw6w6chqvqsh2c6jfsb4pw9bpgdkmjnh-boost-1.87.0-dev/include/boost/regex/v5/basic_regex.hpp:172
#10 0x00007ff4bd7729bd in boost::re_detail_500::basic_regex_implementation<char, boost::regex_traits<char, boost::cpp_regex_traits<char> > >::basic_regex_implementation (this=0x7ff08c009d50)
    at /nix/store/zw6w6chqvqsh2c6jfsb4pw9bpgdkmjnh-boost-1.87.0-dev/include/boost/regex/v5/basic_regex.hpp:212
#11 boost::basic_regex<char, boost::regex_traits<char, boost::cpp_regex_traits<char> > >::do_assign (
    this=this@entry=0x7ff4bd90cad0 <nix::quoteRegexChars(std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&)::specialRegex>, p1=p1@entry=0x7ff4bd580f79 <.L.str.27> "[.^$\\\\*+?()\\[\\]{}|]", p2=0x7ff4bd580f8c <.L.str.27+19> "", f=f@entry=0)
    at /nix/store/zw6w6chqvqsh2c6jfsb4pw9bpgdkmjnh-boost-1.87.0-dev/include/boost/regex/v5/basic_regex.hpp:640
#12 0x00007ff4bd76d593 in boost::basic_regex<char, boost::regex_traits<char, boost::cpp_regex_traits<char> > >::assign (
    this=0x7ff4bd90cad0 <nix::quoteRegexChars(std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&)::specialRegex>, p1=0x7ff4bd580f79 <.L.str.27> "[.^$\\\\*+?()\\[\\]{}|]", p2=0x7ff093ffcc00 "", p2@entry=0x0, f=0)
    at /nix/store/zw6w6chqvqsh2c6jfsb4pw9bpgdkmjnh-boost-1.87.0-dev/include/boost/regex/v5/basic_regex.hpp:387
#13 boost::basic_regex<char, boost::regex_traits<char, boost::cpp_regex_traits<char> > >::assign (
    this=0x7ff4bd90cad0 <nix::quoteRegexChars(std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&)::specialRegex>, p=0x7ff4bd580f79 <.L.str.27> "[.^$\\\\*+?()\\[\\]{}|]", f=0)

yeah i just...

diff --git a/src/libstore/local-gc.cc b/src/libstore/local-gc.cc
index e3c74f357..32a20c0ea 100644
--- a/src/libstore/local-gc.cc
+++ b/src/libstore/local-gc.cc
@@ -66,3 +66,3 @@ Roots findRuntimeRootsUnchecked(const StoreDirConfig & config)
     auto procDir = AutoCloseDir{opendir("/proc")};
-    if (procDir) {
+    if (procDir && false) {
         struct dirent * ent;