This patch adds an include needed since icu59:
Source: https://git.archlinux.org/svntogit/community.git/plain/trunk/icu59.patch?h=packages/aegisub
--- aegisub-3.2.2/src/utils.cpp	2014-12-08 02:07:09.000000000 +0200
+++ aegisub-3.2.2/src/utils.cpp	2017-04-26 11:11:15.438239182 +0300
@@ -44,6 +44,7 @@
 #include <boost/filesystem/path.hpp>
 #include <map>
 #include <unicode/locid.h>
+#include <unicode/unistr.h>
 #include <wx/clipbrd.h>
 #include <wx/filedlg.h>
 #include <wx/stdpaths.h>
 <a href='/guix/'>guix</a></td><td class='form'><form method='get'>
<input type='hidden' name='id' value='a8cae692b2dbfcb6bee18a3f141da2bdd1e1747b'/><select name='h' onchange='this.form.submit();'>
<option value='koszko' selected='selected'>koszko</option>
<option value='koszko-scripts'>koszko-scripts</option>
</select> <input type='submit' value='switch'/></form></td></tr>
<tr><td class='sub'>Wojtek's customized Guix</td><td class='sub right'></td></tr></table>
<table class='tabs'><tr><td>
<a href='/guix/about/'>about</a><a href='/guix/'>summary</a><a href='/guix/refs/?id=a8cae692b2dbfcb6bee18a3f141da2bdd1e1747b'>refs</a><a class='active' href='/guix/log/ROADMAP'>log</a><a href='/guix/tree/ROADMAP?id=a8cae692b2dbfcb6bee18a3f141da2bdd1e1747b'>tree</a><a href='/guix/commit/ROADMAP?id=a8cae692b2dbfcb6bee18a3f141da2bdd1e1747b'>commit</a><a href='/guix/diff/ROADMAP?id=a8cae692b2dbfcb6bee18a3f141da2bdd1e1747b'>diff</a></td><td class='form'><form class='right' method='get' action='/guix/log/ROADMAP'>
<input type='hidden' name='id' value='a8cae692b2dbfcb6bee18a3f141da2bdd1e1747b'/><select name='qt'>
<option value='grep'>log msg</option>
<option value='author'>author</option>
<option value='committer'>committer</option>
<option value='range'>range</option>
</select>
<input class='txt' type='search' size='10' name='q' value=''/>
<input type='submit' value='search'/>
</form>
</td></tr></table>
<div class='path'>path: <a href='/guix/log/?id=a8cae692b2dbfcb6bee18a3f141da2bdd1e1747b'>root</a>/<a href='/guix/log/ROADMAP?id=a8cae692b2dbfcb6bee18a3f141da2bdd1e1747b'>ROADMAP</a></div><div class='content'><table class='list nowrap'><tr class='nohover'><th class='left'>Age</th><th class='left'>Commit message (<a href='/guix/log/ROADMAP?id=a8cae692b2dbfcb6bee18a3f141da2bdd1e1747b&amp;showmsg=1'>Expand</a>)</th><th class='left'>Author</th></tr>
<tr><td><span title='2016-01-29 20:21:54 +0300'>2016-01-29</span></td><td><a href='/guix/commit/ROADMAP?id=171a0a13a4350ac9bbed0f2ed8e9c9777cc57b22'>Rename 'dmd' to 'shepherd' in comments and strings.</a><span class='msg-avail'>...<span class='msg-tooltip'>* build-aux/hydra/demo-os.scm (operating-system)[issue]: Point to
  shepherd instead of dmd.
* ROADMAP: Likewise.
* gnu/build/install.scm (directives): Adjust comment.
</span></span></td><td>Alex Kost</td></tr>
<tr><td><span title='2015-01-22 22:52:11 +0100'>2015-01-22</span></td><td><a href='/guix/commit/ROADMAP?id=5bf6b86f1b5b12a55305b0dc8030a6f8f2005f01'>doc: Update 'ROADMAP'.</a><span class='msg-avail'>...<span class='msg-tooltip'>Suggested by Omar Radwan &lt;toxemicsquire4@gmail.com&gt;.

* ROADMAP: Rewrite.
</span></span></td><td>Ludovic Courtès</td></tr>
<tr><td><span title='2014-01-03 18:19:58 +0100'>2014-01-03</span></td><td><a href='/guix/commit/ROADMAP?id=48ad99db25cf8a60b5d0d3dc333aee89ce8aba8f'>doc: Update 'ROADMAP'.</a><span class='msg-avail'>...<span class='msg-tooltip'>* ROADMAP: Add link to the updated road map, and the a note on release
  history.
</span></span></td><td>Ludovic Courtès</td></tr>
<tr><td><span title='2013-01-22 00:17:42 +0100'>2013-01-22</span></td><td><a href='/guix/commit/ROADMAP?id=476f8ea33ce3791dbe0c77332c92e4351827dcd5'>Update `ROADMAP'.</a></td><td>Ludovic Courtès</td></tr>