Hi Bruno, Bruno Victal writes: >> So this may just need compiler parameters to set C++11 instead of C++17 >> as target. > > Looking at the README file from , > it looks to me that upstream has moved to . (judging by the name of the repo owner) > Can you try asking upstream for a new release? The last commit () > has the message 'Fix c+11 compilation'. I tried to build from the latest commit, but it did not build. But I could now test adding the std argument and that works. $ ./pre-inst-env guix build htmlcxx /gnu/store/3bqrqs2zzx1gy4xc1g9i59z8nnhwv2rs-htmlcxx-0.87 A patch is attached.