Sorry! I notice that was a bit mangled (with a "| sed -e 's/^.*://' "). Here is unmangled, from /var/log/install.log
I might add that I mv'ed the existing things in /usr/bin/ out of the way, with identical results.
Jun 21 15:29:40 Mac-mini Installer[86426]: Aquamacs Command Line Tools Installation Log
Jun 21 15:29:40 Mac-mini Installer[86426]: Opened from: /Users/pgh/src/aquamacs-emacs/nextstep/Aquamacs.app/Contents/Resources/Aquamacs Command Line Tool PreElCapitan.mpkg
Jun 21 15:29:40 Mac-mini Installer[86426]: Product archive /Users/pgh/src/aquamacs-emacs/nextstep/Aquamacs.app/Contents/Resources/Aquamacs Command Line Tool PreElCapitan.mpkg trustLevel=100
Jun 21 15:29:40 Mac-mini Installer[86426]: PackageKit: invalid package /Users/pgh/src/aquamacs-emacs/nextstep/Aquamacs.app/Contents/Resources/Aquamacs Command Line Tool PreElCapitan.mpkg/Contents/Packages/aquamacs.pkg has no bundle identifier
Jun 21 15:29:40 Mac-mini Installer[86426]: External component packages (2) trustLevel=100 (trust evaluation failed)
Jun 21 15:29:45 Mac-mini Installer[86426]: InstallerStatusNotifications plugin loaded
Jun 21 15:29:50 Mac-mini Installer[86426]: LSExceptions [0x6080000b2480] unloaded
Jun 21 15:29:52 Mac-mini runner[86431]: Administrator authorization granted.
Jun 21 15:29:52 Mac-mini Installer[86426]: ================================================================================
Jun 21 15:29:52 Mac-mini Installer[86426]: User picked Standard Install
Jun 21 15:29:52 Mac-mini Installer[86426]: Choices selected for installation:
Jun 21 15:29:52 Mac-mini Installer[86426]: Upgrade: "Aquamacs Command Line Tools"
Jun 21 15:29:52 Mac-mini Installer[86426]: Upgrade: "/usr/bin/aquamacs" at path "//usr/bin"
Jun 21 15:29:52 Mac-mini Installer[86426]: aquamacs.pkg : org.aquamacs.commandlinetools.pkg : 3.1
Jun 21 15:29:52 Mac-mini Installer[86426]: Upgrade: "/usr/bin/emacsclient" at path "//usr/bin"
Jun 21 15:29:52 Mac-mini Installer[86426]: emacsclient.pkg : com.david-reitter.aquamacsCommandLineTools.emacsclient.pkg : 1.1
Jun 21 15:29:52 Mac-mini Installer[86426]: ================================================================================
Jun 21 15:29:52 Mac-mini Installer[86426]: It took 0.00 seconds to summarize the package selections.
Jun 21 15:29:52 Mac-mini Installer[86426]: -[IFDInstallController(Private) _buildInstallPlan]: location = file://localhost
Jun 21 15:29:52 Mac-mini Installer[86426]: -[IFDInstallController(Private) _buildInstallPlan]: file://localhost/Users/pgh/src/aquamacs-emacs/nextstep/Aquamacs.app/Contents/Resources/Aquamacs%20Command%20Line%20Tool%20PreElCapitan.mpkg/Contents/Packages/aquamacs.pkg
Jun 21 15:29:52 Mac-mini Installer[86426]: -[IFDInstallController(Private) _buildInstallPlan]: file://localhost/Users/pgh/src/aquamacs-emacs/nextstep/Aquamacs.app/Contents/Resources/Aquamacs%20Command%20Line%20Tool%20PreElCapitan.mpkg/Contents/Packages/emacsclient.pkg
Jun 21 15:29:52 Mac-mini Installer[86426]: Set authorization level to root for session
Jun 21 15:29:52 Mac-mini Installer[86426]: PackageKit: invalid package /Users/pgh/src/aquamacs-emacs/nextstep/Aquamacs.app/Contents/Resources/Aquamacs Command Line Tool PreElCapitan.mpkg/Contents/Packages/aquamacs.pkg has no bundle identifier
Jun 21 15:29:52 Mac-mini Installer[86426]: Package file://localhost/Users/pgh/src/aquamacs-emacs/nextstep/Aquamacs.app/Contents/Resources/Aquamacs%20Command%20Line%20Tool%20PreElCapitan.mpkg/Contents/Packages/aquamacs.pkg not supported by PK
Jun 21 15:29:52 Mac-mini Installer[86426]: Will use IF session
Jun 21 15:29:52 Mac-mini Installer[86426]: -[IFPkg(Info_Conversion_Private) _parseOldStyleForLanguage:] - can't find .info file (aquamacs)
Jun 21 15:29:52 Mac-mini Installer[86426]: The package "aquamacs" could not be opened. This can happen if the package has incorrect permissions or if the package has been renamed.
Jun 21 15:29:52 Mac-mini Installer[86426]: PFPackage::packageWithURL - can't instantiate package: /Users/pgh/src/aquamacs-emacs/nextstep/Aquamacs.app/Contents/Resources/Aquamacs Command Line Tool PreElCapitan.mpkg/Contents/Packages/aquamacs.pkg
Jun 21 15:29:52 Mac-mini Installer[86426]: Error opening package "aquamacs.pkg".
Jun 21 15:29:52 Mac-mini Installer[86426]: Install failed: The Installer could not install the software because there was no software found to install.
Jun 21 15:29:52 Mac-mini Installer[86426]: IFDInstallController 17280 state = 8
Jun 21 15:29:52 Mac-mini Installer[86426]: Displaying 'Install Failed' UI.
Jun 21 15:29:52 Mac-mini Installer[86426]: 'Install Failed' UI displayed message:'The Installer could not install the software.
Jun 21 15:50:17 Mac-mini softwareupdated[72329]: Scan for changed products with previous 0 updates: (plus 135 predicate-only)
Jun 21 15:50:17 Mac-mini softwareupdated[72329]: SoftwareUpdate: Scan for client pid 72329 (/System/Library/CoreServices/Software Update.app/Contents/Resources/softwareupdated)
Jun 21 15:50:17 Mac-mini softwareupdated[72329]: Adding client SUUpdateServiceClient pid=86505, uid=501, installAuth=NO rights=(), transactions=0 (/System/Library/Frameworks/WebKit.framework/Versions/A/XPCServices/com.apple.WebKit.WebContent.xpc/Contents/MacOS/com.apple.WebKit.WebContent)
Jun 21 15:50:18 Mac-mini softwareupdated[72329]: SoftwareUpdate: Catalog Not Modified since last scan ("574d0-535be43141040")
Jun 21 15:50:18 Mac-mini softwareupdated[72329]: SoftwareUpdate: Using catalog
https://swscan.apple.com/content/catalogs/others/index-10.10-10.9-mountainlion-lion-snowleopard-leopard.merged-1.sucatalog.gzJun 21 15:50:18 Mac-mini softwareupdated[72329]: Added 267 PPD versions for /Library/Printers/PPDs/Contents/Resources from cache as of 2015-06-19 07:08:37 +0000
Jun 21 15:50:18 Mac-mini softwareupdated[72329]: SoftwareUpdate: elapsed scan time = 0.7
Jun 21 15:50:18 Mac-mini softwareupdated[72329]: Scan (f=0, d=0) found 0 updates: (plus 135 predicate-only)
Jun 21 15:50:18 Mac-mini softwareupdated[72329]: Ramped updates marked
Jun 21 15:50:27 Mac-mini softwareupdated[72329]: Removing client SUUpdateServiceClient pid=86505, uid=501, installAuth=NO rights=(), transactions=0 (/System/Library/Frameworks/WebKit.framework/Versions/A/XPCServices/com.apple.WebKit.WebContent.xpc/Contents/MacOS/com.apple.WebKit.WebContent)
Should add that actually using the git-derived Aquamacs.app "in anger" for real work (involving auctex, haskell-mode and several other things) seems so far fine.
Hardly ever use the command-line tools.
Peter