Hi Lucas, thanks for the bug report.
I first thought this seems to have changed with gcc 10.2 instead 10.1 since I had gcc 10 as default locally for quite while before it became default. But at least my last local 0.8.13-1 build was done with still gcc 9. Also verified that it's not just an issue between gcc 10.1 and 10.2 by downgrading gcc-10 and friends to 10.1.0-6 from testing: Didn't fix this. So it might be a general FTBFS with gcc 10 — although I'm surprised this didn't came up earlier. Lucas Nussbaum wrote: > Relevant part (hopefully): Seems to boil down to these: → fgrep "no known conversion" ../aptitude_0.8.13-2_amd64.build | sort -u ../../../../src/generic/views/download_progress.cc:47:89: note: no known conversion for argument 2 from ‘const char [10]’ to ‘const aptitude::views::download_progress::file_progress&’ ../../../../src/generic/views/download_progress.cc:47:89: note: no known conversion for argument 2 from ‘const char [17]’ to ‘const aptitude::views::download_progress::file_progress&’ ../../../../src/generic/views/download_progress.cc:47:89: note: no known conversion for argument 2 from ‘const char [18]’ to ‘const aptitude::views::download_progress::file_progress&’ ../../../../src/generic/views/download_progress.cc:47:89: note: no known conversion for argument 2 from ‘const char [2]’ to ‘const aptitude::views::download_progress::file_progress&’ ../../../../src/generic/views/download_progress.cc:47:89: note: no known conversion for argument 2 from ‘const char [3]’ to ‘const aptitude::views::download_progress::file_progress&’ ../../../../src/generic/views/download_progress.cc:47:89: note: no known conversion for argument 2 from ‘const char [6]’ to ‘const aptitude::views::download_progress::file_progress&’ ../../../../src/generic/views/download_progress.cc:47:89: note: no known conversion for argument 2 from ‘const char [7]’ to ‘const aptitude::views::download_progress::file_progress&’ ../../../../src/generic/views/download_progress.cc:47:89: note: no known conversion for argument 2 from ‘const long unsigned int’ to ‘const aptitude::views::download_progress::file_progress&’ ../../../../src/generic/views/download_progress.cc:97:63: note: no known conversion for argument 2 from ‘const char [18]’ to ‘const aptitude::views::download_progress::status&’ ../../../../src/generic/views/download_progress.cc:97:63: note: no known conversion for argument 2 from ‘const char [2]’ to ‘const aptitude::views::download_progress::status&’ ../../../../src/generic/views/download_progress.cc:97:63: note: no known conversion for argument 2 from ‘const char [3]’ to ‘const aptitude::views::download_progress::status&’ ../../../../src/generic/views/download_progress.h:271:63: note: no known conversion for argument 2 from ‘const char [10]’ to ‘const aptitude::views::download_progress::status&’ ../../../../src/generic/views/download_progress.h:271:63: note: no known conversion for argument 2 from ‘const char [17]’ to ‘const aptitude::views::download_progress::status&’ ../../../../src/generic/views/download_progress.h:271:63: note: no known conversion for argument 2 from ‘const char [2]’ to ‘const aptitude::views::download_progress::status&’ ../../../../src/generic/views/download_progress.h:271:63: note: no known conversion for argument 2 from ‘const char [6]’ to ‘const aptitude::views::download_progress::status&’ ../../../../src/generic/views/download_progress.h:271:63: note: no known conversion for argument 2 from ‘const char [7]’ to ‘const aptitude::views::download_progress::status&’ ../../../../src/generic/views/download_progress.h:271:63: note: no known conversion for argument 2 from ‘const long unsigned int’ to ‘const aptitude::views::download_progress::status&’ And this seems to be the hints what might help: → fgrep "candidate" ../aptitude_0.8.13-2_amd64.build | sort -u ../../../../src/generic/views/download_progress.cc:47:19: note: candidate: ‘std::ostream& aptitude::views::operator<<(std::ostream&, const aptitude::views::download_progress::file_progress&)’ ../../../../src/generic/views/download_progress.cc:96:19: note: candidate: ‘std::ostream& aptitude::views::operator<<(std::ostream&, const aptitude::views::download_progress::status&)’ ../../../../src/generic/views/download_progress.h:270:19: note: candidate: ‘std::ostream& aptitude::views::operator<<(std::ostream&, const aptitude::views::download_progress::status&)’ /usr/include/c++/10/bits/basic_string.h:6458:5: note: candidate: ‘template<class _CharT, class _Traits, class _Alloc> std::basic_ostream<_CharT, _Traits>& std::operator<<(std::basic_ostream<_CharT, _Traits>&, const std::__cxx11::basic_string<_CharT, _Traits, _Allocator>&)’ /usr/include/c++/10/bits/shared_ptr.h:69:5: note: candidate: ‘template<class _Ch, class _Tr, class _Tp, __gnu_cxx::_Lock_policy _Lp> std::basic_ostream<_CharT, _Traits>& std::operator<<(std::basic_ostream<_CharT, _Traits>&, const std::__shared_ptr<_Tp, _Lp>&)’ /usr/include/c++/10/cstddef:125:5: note: candidate: ‘template<class _IntegerType> constexpr std::__byte_op_t<_IntegerType> std::operator<<(std::byte, _IntegerType)’ /usr/include/c++/10/string_view:622:5: note: candidate: ‘template<class _CharT, class _Traits> std::basic_ostream<_CharT, _Traits>& std::operator<<(std::basic_ostream<_CharT, _Traits>&, std::basic_string_view<_CharT, _Traits>)’ /usr/include/c++/10/system_error:262:5: note: candidate: ‘template<class _CharT, class _Traits> std::basic_ostream<_CharT, _Traits>& std::operator<<(std::basic_ostream<_CharT, _Traits>&, const std::error_code&)’ Admittedly my C++ knowledge doesn't go deep enough to understand where I might put these. Hopefully Manuel or someone else can chime in. Regards, Axel -- ,''`. | Axel Beckert <a...@debian.org>, https://people.debian.org/~abe/ : :' : | Debian Developer, ftp.ch.debian.org Admin `. `' | 4096R: 2517 B724 C5F6 CA99 5329 6E61 2FF9 CD59 6126 16B5 `- | 1024D: F067 EA27 26B9 C3FC 1486 202E C09E 1D89 9593 0EDE