<div dir="ltr"><div class="gmail_quote"><div dir="ltr">Thank you very much for your reply.<div>I did try "sudo apt-get install libdwarf-dev"but "libdwarf not found. Disabling Backtrace support." does't disappear.</div><div>and in and only in file apitrace/thirdparty/libbacktrace/CMakeLists.txt,  I found:</div><div>"</div><div><div>include (CheckIncludeFile)</div><div>check_include_file (dwarf.h HAVE_DWARF_H)</div><div>check_include_file (libdwarf/dwarf.h HAVE_LIBDWARF_DWARF_H)</div><div>if (NOT HAVE_DWARF_H AND NOT HAVE_LIBDWARF_DWARF_H)</div><div>    set (FORMAT_FILE unknown.c)</div><div>    set (BACKTRACE_SUPPORTED 0)</div><div>    message (STATUS "libdwarf not found. Disabling Backtrace support.")</div><div>endif ()</div></div><div><br></div><div>"</div><div>so I think the “dwarf.h” file is the key to let known <span style="font-size:12.8000001907349px">libdwarf installed, though I don't know why to do that in this way if </span><span style="font-size:12.8000001907349px"> </span><a href="https://github.com/apitrace/apitrace/blob/4aeb41d853864fa57f3d21a61bd86b1161e5ff8b/.travis.yml#L13" style="font-size:12.8000001907349px" target="_blank">https://github.com/apitrace/apitrace/blob/4aeb41d853864fa57f3d21a61bd86b1161e5ff8b/.travis.yml#L13</a> works well.</div><div> </div><div><span style="color:rgb(80,0,80);font-size:12.8000001907349px">Best regards</span><br></div></div><div class="HOEnZb"><div class="h5"><div class="gmail_extra"><br></div></div></div></div></div>