Inkscape svn trunk stopped building for me on Gentoo Linux ~x86 about two weeks ago, which corresponds somewhat with the last commit on xtension/internal/pdfinput/pdf-parser.cpp.
The build.log is huge, but available if it helps anyone debug.
# grep error: build.log extension/internal/pdfinput/pdf-parser.cpp:2259: error: expected primary-expression before '<<' token extension/internal/pdfinput/pdf-parser.cpp:2259: error: expected primary-expression before '<<' token extension/internal/pdfinput/pdf-parser.cpp:2259: error: expected primary-expression before '<<' token extension/internal/pdfinput/pdf-parser.cpp:2259: error: expected primary-expression before '<' token extension/internal/pdfinput/pdf-parser.cpp:2259: error: expected primary-expression before '.' token extension/internal/pdfinput/pdf-parser.cpp:2261: error: expected primary-expression before '==' token extension/internal/pdfinput/pdf-parser.cpp:2261: error: expected primary-expression before '==' token extension/internal/pdfinput/pdf-parser.cpp:2261: error: expected primary-expression before '==' token extension/internal/pdfinput/pdf-parser.cpp:2261: error: expected primary-expression before '=' token extension/internal/pdfinput/pdf-parser.cpp:2316: error: expected primary-expression before '<<' token extension/internal/pdfinput/pdf-parser.cpp:2316: error: expected primary-expression before '<<' token extension/internal/pdfinput/pdf-parser.cpp:2316: error: expected primary-expression before '<<' token extension/internal/pdfinput/pdf-parser.cpp:2316: error: expected primary-expression before '<' token extension/internal/pdfinput/pdf-parser.cpp:2316: error: expected primary-expression before '.' token extension/internal/pdfinput/pdf-parser.cpp:2318: error: expected primary-expression before '==' token extension/internal/pdfinput/pdf-parser.cpp:2318: error: expected primary-expression before '==' token extension/internal/pdfinput/pdf-parser.cpp:2318: error: expected primary-expression before '==' token extension/internal/pdfinput/pdf-parser.cpp:2318: error: expected primary-expression before '=' token
P.S. The pdf-parser's issues with the public vs. private parts of the poppler API have been the only real source of build failures for me over the past year. Perhaps r19370 is central to fixing that. Still, It would be nice if a config option allowed it to be skipped entirely when there's trouble.
(old, since fixed)
pdfinput/pdf-parser.cpp:2248: error: no matching function for call to GfxFont::getNextChar
pdf-input.cpp:544: error: '_preview_output_dev' was not declared in this scope